The Adventure of the Plush Shark

Summary:

"Have you ever been to the shark tank at the London Aquarium, John?"

Just before "His Last Vow". John and Mary are on honeymoon. Sherlock finds himself with time to kill. Archie solves his first case.

Author's Note:

The concept of Sherlock being able to hear the radio frequency of a transmitting CCTV camera is straight from GhyllWyne's epic sequence of missing moments from TRF and TEH, "Something Broken", here on the site.

And while I'd love to go there one day, the one thing that I seem to have in common with John Watson (other than a deep affection for his flatmate) is that I've never been to the London Aquarium either. So the layout of its interior, as seen in this story, is totally a product of artistic licence on my part. Don't sue me.

Sincere thanks to my beta reader Cooklet for the language help and the trial run!

London. The small square between the County Hall and Jubilee Gardens, on the south bank of the Thames, close to the London Eye.A bright, sunny and very hot summer afternoon. Crowds of people are milling around, tourists and locals alike, all in light summer clothes, many with sunglasses or even sun hats, not a few with ice-cream cones in their hands, some making their way to one of the many attractions in the area, some taking a rest one of the stone benches. On one of these stone benches, Sherlock Holmes is sitting with his elbows on his knees, his eyes fixed on the phone in his hands, typing on it very rapidly with both thumbs, apparently oblivious to the merry chatter and hum of activity around him. In acknowledgment of the weather, he is in a white shirt – no jacket, let alone his coat - and has even rolled up the sleeves to his elbows. From across the river, Big Ben can be heard striking the quarter of an hour. Sherlock, visibly annoyed, glances up at the clock, which is at a quarter past three, then returns his gaze to the screen of his phone. In close-up, we can see that he is actually playing Tetris on his phone at an absolutely insane speed, the pieces descending and the completed rows disappearing quicker than the eye can follow. Then all of a sudden, the screen turns dark, the phone beeps, and a technical error message appears on the screen. Sherlock nods, looking content.

BOY'S VOICE (off-screen, very loudly and excitedly): There he is, mum! Over there!

Sherlock looks up in the direction of the voice and sees Archie making his way straight across the square towards him, with his mother in tow. She, in a miniskirt and on high heels, can hardly keep up with her son, who jostles his way through the crowds in a great hurry. She carries a designer handbag over her shoulder and a large gym bag in glaring neon colours in her hand. Sherlock pockets his phone and stands up to meet them. Both Archie and his mum are rather out of breath by the time they reach him. Archie, beaming, lets go of his mother's hand and looks as if he's going to run straight to Sherlock for another bear hug like at Mary and John's wedding, but Sherlock rather abruptly holds out his hand, effectively blocking the attempted embrace. Archie, not put out in the least, instead takes Sherlock's hand and shakes it, looking touchingly grave and grown-up.

SHERLOCK: Hello, Archie. Nice to see you again.

ARCHIE (beaming again): Hi.

Sherlock smiles back at him, then turns to Archie's mother, and his smile takes on a slightly fixed quality. He does not offer her his hand.

ARCHIE'S MUM (still somewhat breathlessly): I'm so sorry we're a bit late. I know every minute of your time is of value.

A corner of Sherlock's mouth twitches, but she doesn't seem to notice.

ARCHIE'S MUM: It's so good of you to step in for John, I know it was supposed to be his present, but then Archie was so upset when I told him we'd have to wait for them to come back, and -

Sherlock, who is evidently not listening with anything but the very surface of his mind, lets his eyes travel over her in a rapid glance, taking in her careful make-up and her jewellery – most notably, long dangling earrings – her low-cut blouse and miniskirt. He's doing it far too quickly to cause offence, but he still manages to disconcert her quite a bit. She blushes, and hurries on.

ARCHIE'S MUM: - and to tell you the truth, Archie wouldn't have wanted to go with John anyway if he could go with you instead, so -

SHERLOCK (cutting her off): It's alright, you know. John will be paying for the tickets. And I'm free until nightfall.

He smiles ominously, unsettling her even further. Archie looks up at him, round-eyed with excitement.

ARCHIE'S MUM: Alright then – (to Archie) Be good, yeah? And have fun. (To Sherlock, apologetically) And thanks for giving me a chance to get back into shape a bit. (She holds up her gym bag in explanation.) I don't get that very often.

The phone in her handbag starts ringing.

SHERLOCK (pointedly): And that's probably your gym instructor telling you you're running late for your session.

Archie's mum blushes again. She fumbles to get her phone out of her bag and hastily ends the call without taking it.

ARCHIE'S MUM (flustered): Right. (To Archie, putting her hand on his shoulder in a quick caress) Have a lovely afternoon. (To Sherlock) Thanks again.

She hitches her bag up on her shoulder, obviously desperate to be going.

SHERLOCK (generously): Well, see you later. Enjoy your workout.

She more grimaces than smiles, then turns and hurries away.

ARCHIE (excitedly): What happens at nightfall?

SHERLOCK (drily): EastEnders repeats. Wouldn't miss them for the world.

Archie looks severely disappointed. Sherlock glances down at him and grins.

SHERLOCK: C'mon.

And they start walking together towards the entrance to the London Aquarium.

Some minutes later, they're in the foyer, already past the ticket barriers. Blue-greenish light engulfs them, in a marked contrast to the bright sunshine outside. The entrance hall is huge, encompassing two storeys, the ground floor laid with blue flagstones, and on either side, a flight of stairs giving access to a gallery that runs around three sides of the hall on the upper level. The place is quite busy, but in spite of the crowds, there is a hushed atmosphere. Archie looks around with wide eyes at the larger-than-life photographies of maritime creatures covering the walls of the hall. Sherlock puts their tickets into the pocket of his shirt and studies a leaflet with the floor plan that he has obviously picked up at the ticket booth.

SHERLOCK: Alright. D'you want to see the animals in alphabetical order, in geographical order, or do we just follow the suggested tour?

ARCHIE: I wanna see the sharks!

SHERLOCK: Just the sharks?

ARCHIE: First the sharks, and then all the rest.

SHERLOCK: Fine.

He starts walking purposefully down the hall and into a passage leading off it, Archie hurrying after him to keep up. The passage forks. A signpost reading "Tour" points to the right. They turn left.

Soon after, they're in the shark tunnel, a stunning structure of ultra-thick glass that allows the visitors to pass straight through the shark tank, with water on both sides and above their heads. Standing side by side in the middle of the domed passage, Archie and Sherlock are watching the huge creatures as they swim by. Archie's mouth is hanging open in fascination.

ARCHIE (his eyes on a particularly large specimen): Have you seen that movie where the shark eats people whole?

SHERLOCK (after a moment's deliberation): As a matter of fact, I've seen that live.

ARCHIE (turning to Sherlock, wide-eyed): Really? Cool!

Sherlock smiles a rather strained smile.

ARCHIE: Did it really eat someone up? Just like that?

SHERLOCK: It bit off a leg, just like that. And the victim lost enough blood to die only moments after he was fished out of the water.

ARCHIE: Where was that? Was it a case? Someone tripped a man into a shark basin to kill him or something?

SHERLOCK: No. I just happened to witness it from a boat I was on at the time. Nothing to do with the case.

ARCHIE: What was the case?

SHERLOCK: Maritime insurance fraud.

ARCHIE: Mary what?

SHERLOCK (with a shrug): Never mind. It was quite unexciting, really. The only part of it that would theoretically have been worth the jet lag was a cruise on my client's yacht down Sydney Harbour, if it hadn't been for that incident.

ARCHIE (hesitantly, as if unsure whether he really wants to hear the answer): Did he scream a lot?

SHERLOCK: Quite, yes.

ARCHIE: Why did he go into the water at all, if there were sharks?

SHERLOCK: He climbed over the shark-netting across a beach, as a dare. His older brother egged him on. Their parents didn't see it until it was too late.

ARCHIE: Their parents?

SHERLOCK: Yes. Didn't I mention that he was a boy about your own age?

Archie stands dumbfounded, eyebrows drawn together in a pained expression. Then he swallows, and turns back to look thoughtfully at the sharks passing them on both sides. A large portion of his former enthusiasm seems to have evaporated. Sherlock is watching him out of the corner of his eyes. After a long moment of silence, Archie turns back to Sherlock.

ARCHIE (obviously desperate to change the subject): So you know how to sail a boat?

SHERLOCK: In theory, yes. (He smiles.) In practice, I just get seasick.

They both crack up laughing, and they're still laughing when a particularly long and thin shark passes very close to the glass wall of the tank, so close that Archie inadvertently takes a hasty step backwards. Sherlock puts a steadying hand on his shoulder. They both follow it with their eyes as it turns in a smooth, almost graceful volte-face and comes gliding back the way it came. As it again passes the spot where Sherlock and Archie are standing, it turns its head sideways a little so it seems to be looking directly at them with its tiny, cold eyes. Archie, no longer laughing, gives a shudder.

ARCHIE: It was looking at me!

SHERLOCK: Well, you were looking at it, too. Can't blame it for returning the compliment. (In a reassuring tone) There are almost five hundred different species of sharks, you know, but only four of those have ever been reported to attack humans unprovoked.

ARCHIE: Is this one?

Sherlock checks the chart depicting the different species in the tank that has been set up on a presentation board in front of the glass wall.

SHERLOCK: Actually, yes.

Archie grimaces.

SHERLOCK: But sharks don't have very good eyesight. They rely a lot more on their senses of smell and hearing to find their prey. They can smell one part of blood in a million parts of saltwater, and they know exactly where to go to find the source of it. (He glances at his little friend.) Difficult to smell through a glass wall, though.

Archie nods, reassured. He ambles along the tunnel for a few paces, then stops again, his eyes on a smaller specimen gliding past.

ARCHIE: They grin, don't they? All the time.

SHERLOCK: That's only what you're seeing.

ARCHIE: No, look! That one grins, totally.

He points, and Sherlock steps very close to the wall of the tank.

SHERLOCK (after a moment of silent observation, intrigued): They never blink, at any rate. What's the point of having eyelids if you never blink?

ARCHIE: Really? That'd be cool. Pete always beats me at that.

SHERLOCK (distracted): At what?

ARCHIE: Staring contest. You blink, you lose. I always do. I hate it.

Sherlock regards him for a moment with a very thoughtful expression on his face. A shadow falls across them. They both glance up at the transparent ceiling of the tunnel. The long thin shark they saw earlier has just passed them again.

SHERLOCK (bracing himself): Well. Want to see something else now?

ARCHIE: Alright.

As they leave the shark tunnel and continue along a passage lined with small tanks with seahorses in them, the phone in Sherlock's pocket rings. He takes it out, glances at the caller ID, and stops short.

SHERLOCK (to Archie): Just a second, OK?

Archie nods absently and turns to look at the seahorses. Sherlock takes the call.

SHERLOCK (into the phone, in a surprisingly gentle, almost appeasing tone): Hi. I know what you're going to say now. No, of course I know it, I didn't mean - (He listens to the reply.) Yeah, exactly. Look, this isn't the best time to be talking. I'll call you when I'm free, alright? (Another pause. Affectionately) Yeah, you too.

He ends the call – and is quite surprised to find Archie looking at him with great interest.

ARCHIE (immediately): Your girlfriend?

SHERLOCK: What makes you think that?

ARCHIE: It's what my mum always says when Simon calls her and I'm around. (In an uncanny imitation of his mother's embarrassed and slightly hectic voice) "This isn't the best time to be talking."

He rolls his eyes.

SHERLOCK: Your mum's boyfriend?

ARCHIE (in an off-hand tone): Yeah. The one she goes to meet when she pretends to go to the gym.

Sherlock, rather taken aback yet again, gives Archie a look of genuine respect. Archie meets his eyes, and shrugs.

SHERLOCK: You don't like him?

ARCHIE: Dunno. He doesn't talk to me. Or when he does, it's like he thinks I'm a baby.

He shrugs again and turns back to the seahorses. Sherlock regards him with covert sympathy. Then Archie turns back abruptly and nods at the phone that Sherlock is still holding in his hand.

ARCHIE (in a different tone, genuinely interested): Is she nice, then?

SHERLOCK: Yeah, sure. You've met her. Janine. One of the bridesmaids at John and Mary's wedding.

ARCHIE: Ah. The fat one, the stupid one, or the pretty one?

Sherlock gives Archie a disapproving look, punches a few buttons on his phone and holds it out to him. A portrait shot of a smiling Janine, looking stunning in her bridesmaid's dress with her dark tresses tumbling down over her bare shoulders, fills the screen.

ARCHIE (with the air of an expert): I thought so.

SHERLOCK (drily): Well, I'm glad you approve. (He flicks Janine's image away and pockets his phone.) Right. What's next?

The turtle hall. A number of halls, a dozen tanks and probably a hundred strange forms of maritime life later, this is where Sherlock and Archie have relocated. One side of the large room is filled with a glass wall offering a view into the turtle tank. Three or four of the creatures can be seen moving around in it, very slowly and sedately. A group of schoolchildren are sitting in a semi-circle on the tiled floor in front of the tank, listening to their teacher explaining something about the animals. They have piled their backpacks in a corner near the exit of the hall. At the wall opposite the tank, a number of benches have been installed for the visitors. Sherlock and Archie are side by side on one of them, Archie sitting on his hands, dangling his legs and staring into space, Sherlock with his elbows on his knees, studying the floor plan leaflet. Archie looks rather tired by now, a little overwhelmed by all he has seen, and Sherlock seems content with taking a little break, too. A family passes between them and the turtle tank, blocking their view of the animals. The family consists of a mother, high-heeled and very elegantly dressed, steering a designer pushchair with a toddler sitting in it; a boy about Archie's own age with gelled-back blonde hair; and a South American au pair girl holding blonde twin girls by the hands. The girls look about five years old and are dressed in identical, shockingly pink Barbie doll outfits. All four children look about as overwhelmed and ready for a break as Archie does. The toddler in the pushchair is squirming uncomfortably in his seat, whining and complaining; the girls are snuggled up against the au pair's sides, yawning and shuffling their feet; and when the mother looks the other way, the older boy gives his little brother a vicious pinch in the arm. The little one howls in pain.

A CCTV control room, somewhere behind the scenes in the Aquarium. Two men in the uniforms of security guards – white shirts, black trousers - sit at a large desk in front of several monitors with grainy images from the surveillance cameras on them, all depicting different parts of the Aquarium. The image on the top left screen jumps to a view of the turtle hall, with the pile of backpacks in the foreground.

FIRST SECURITY GUARD (irritated): And when will they ever learn to keep their stuff close by and not leave it lying around?

The second security guard grunts by way of agreement. The image on the top left jumps to a view of Sherlock and Archie on their bench.

SECOND SECURITY GUARD (pointing at the screen): Oh, look. That's a cute pair.

He types on the computer controlling the cameras to stop the image jumping to another camera.

FIRST SECURITY GUARD (leaning in for a closer look, with a laugh): Yeah. That bloke's got the result of his paternity test written all over his face, hasn't he?

SECOND SECURITY GUARD (chuckling): Nice of him to save us taxpayers the expense.

At that exact moment, Sherlock looks up and directly into the camera, frowning. The security guards both give a little jump.

SECOND SECURITY GUARD (only half-joking): I think he heard you, Barry.

FIRST SECURITY GUARD (close to the screen again for a better look): You know what? I think I've seen that face before. (He scratches his head.) Can't remember where, right now.

SECOND SECURITY GUARD (annoyed): Oh, come on. You thought you saw the Beckhams walking through here yesterday, too, and the Duke and Duchess of Cambridge the day before that.

FIRST SECURITY GUARD (equally annoyed): Well, never mind. And now turn it back to normal, Nick, or we'll get in trouble.

The second security man types on the computer again, and the image on the monitor jumps back to a view of the schoolchildren's backpacks.

Back in the turtle hall,the family with the pushchair are moving towards the exit, and their place in front of the tank – blocking Sherlock and Archie's view again – is taken by an Indian family; a father pushing a wheelchair and a mother walking at its side, holding the hand of a severely disabled teenage girl. The girl seems to stare into nothingness, her head moving erratically from side to side, but when they come to a halt in front of the turtle tank, her eyes focus on one of the slowly moving creatures, and a broad smile lights up her whole face. The parents, seeing it, beam at her, and the mother pats the girl's hand proudly. Next, a third family walks across the scene, American tourists in baseball caps and cheap souvenir t-shirts - the father in a London one, the mother in a Michelangelo one, and two boys both in Disneyland Paris ones – and all equally overweight. The boys run up to the tank and start banging their hands against the glass to stir up the turtles. The father immediately calls them to order, and they grudgingly stop misbehaving. The schoolteacher glances at them disapprovingly, then continues her discourse on the turtles as the Americans move away. The pupils are beginning to get a little bored and restless by now, too, shifting and murmuring. Archie yawns.

ARCHIE: Let's go. Nothing happens here.

SHERLOCK: On the contrary.

ARCHIE: What?

SHERLOCK: On the contrary. Something very irregular has just happened in this room, and in a minute or two, someone will discover it and raise an alarm. And then we'll be needed.

ARCHIE: For what?

SHERLOCK: To solve the case.

He glances sidelong at Archie and smiles. Archie stares back at him.

ARCHIE (excitedly): The case? You mean a real case? Like a murder, or something?

SHERLOCK: No, not a murder. Let's not start too ambitiously. But a real crime.

ARCHIE: What crime?

SHERLOCK: Theft. (He points at the pile of the schoolchildrens' backpacks in the corner of the room.) See the red and orange one over there? That backpack has changed its position within the last five minutes, although none of the pupils has been near it.

ARCHIE (frowning): It slipped? Or someone kicked it aside on the way out?

SHERLOCK: No. It was lying flat on the ground when we came in here, now it's propped upright against that big blue one. That didn't happen by itself, or by chance.

ARCHIE: But what did they steal?

At that moment, the schoolteacher claps her hands a couple of times to get her pupils' attention.

SCHOOLTEACHER: And now get out your pens and your workbooks, and let's do the bit on turtles straight away!

The pupils get up and move over into the corner to retrieve their backpacks. Only a moment later, a girl pipes up.

SCHOOLGIRL: Miss Manning, Miss Manning! My purse is gone!

An excited babbling rises from the schoolchildren as they all group around the girl and their teacher. The girl – a pretty little redhead - begins to cry. Sherlock gives Archie a pointed look.

SHERLOCK: And now they will waste about ten precious minutes in checking, double-checking and lamenting what has happened, and when they finally realise that the only chance they have to catch the thief means that they will have to think clearly and act quickly, it will be far too late.

Archie jumps up from his seat.

ARCHIE: But you can catch them!

SHERLOCK: No, you can. (He smiles.) This is your case.

ARCHIE (enthusiastically): Alright! Let's go!

SHERLOCK: Where?

ARCHIE: Catch the thief!

SHERLOCK: And who are we looking for?

ARCHIE (after a moment's reflection, slightly crestfallen): Oh. Right. (Restless again) But we can't just sit here!

SHERLOCK: You can remain standing if you like. (Didactically) Now, think. That's how it's done. Don't rush off madly without a clear idea what you're looking for, alright? Who went through this room after we came here, and left again before the theft was discovered?

ARCHIE (with complete conviction): It was the Americans!

SHERLOCK: Why them?

ARCHIE: 'Cause they're fat and ugly!

Sherlock gives Archie a disapproving look.

SHERLOCK: That wasn't a crime, last time I looked.

ARCHIE (sulkily): It's true though.

SHERLOCK: And what motive would they have, anyway? What use would they have for that purse? They'll probably be in Berlin tonight, in Prague tomorrow, and on their way home the day after that. No point in stealing pound sterling from a British schoolgirl.

ARCHIE (biting his lip): Right.

SHERLOCK: Who came before them?

ARCHIE: That girl –

He apes the erratic head movements of the disabled girl.

SHERLOCK (very sharply): Archie!

Archie looks slightly guilty.

SHERLOCK (still displeased): And now you tell me why not.

ARCHIE: What, the parents? Maybe they're poor.

SHERLOCK: So poor that they'd cough up forty quid for the tickets just to see their daughter smile?

Archie shrugs.

SHERLOCK: So, there remains - ?

ARCHIE: The posh family?

SHERLOCK: Exactly.

ARCHIE (with a frown): But they looked really rich! Did you see the boy's trainers? D'you know what they cost? I've been pestering mum -

SHERLOCK: So, why would someone rich want to steal a schoolgirl's pocket money? Not because they need it.

ARCHIE: Why then?

SHERLOCK (pointing): How did you feel after you'd looked at those turtles for a while, Archie? Those excruciatingly slow-moving, completely uninspiring creatures?

ARCHIE (with a shrug): Dunno. Just bored.

SHERLOCK: Precisely. (He stands up.) Did you see him pinch his little brother just for the fun of it? Boredom makes people do the strangest and unhealthiest things, Archie. Never underestimate boredom as a motive force. It accounts for over seventy-five percent of all petty crime committed in the United Kingdom by the age group of eight to twenty-four year-

ARCHIE (not listening, giddy with excitement): Then what are we doing here! Let's catch him!

SHERLOCK (with a grin): Right. C'mon!

And they rush out of the room, past the group of schoolchildren and their teacher, who are clearly still busy double-checking and lamenting, and out into the passage leading away from the turtle hall. The passage forks again, a sign marked "Exit" pointing to the right, a sign marked "Tour" pointing to the left. Archie turns to take the right hand way.

SHERLOCK: No, left here!

Archie skitters to a halt.

ARCHIE: Why?

SHERLOCK: He won't be in a hurry to leave. He'll give himself away if he makes straight for the exit. Besides, he's got to stay with his family.

ARCHIE (breathlessly): But then he could be anywhere!

SHERLOCK: He's a nine year old boy. Where would he want to go most?

ARCHIE (after a moment's deliberation): The sharks?

SHERLOCK: Yes!

And they start off at top speed into the right hand passage. This part of the Aquarium is busier than the turtle hall, and they have to slow down a bit, weaving in and out of the other visitors, Archie even jostling one or two of them, and earning himself some very irritated looks. Just as the passage widens into the entrance of the shark tunnel, Archie stumbles and bumps into an elderly man. He falls onto his knees, clutching at the man for support. The man gives a shout of alarm and anger. Sherlock, right behind Archie, hooks his hands under his little friend's arms and unceremoniously puts him onto his feet again.

SHERLOCK (to the elderly man, politely): I'm very sorry, sir. Are you alright? (To Archie) And you keep the collateral damage to a minimum, please!

ARCHIE (distracted): What?

SHERLOCK (loudly): Look - where - you're - going!

They run on, the elderly man shaking his head after them. They pass through the entire shark tunnel again, but there is no sign of the posh family. Archie stops when they reach the other end, looking severely disappointed.

ARCHIE: We're too late!

SHERLOCK: Hmm. Looks like it.

ARCHIE: What now?

SHERLOCK: Back down to the exit. We'll wait for them there.

ARCHIE: We'll never catch up!

SHERLOCK: Nonsense. We haven't got wheels. We'll overtake them on the stairs while they wait for the lift.

And he starts off again in the direction they've just come from. Archie runs after him.

The CCTV control room. The first security guard is on his feet, his eyes on the screen in the bottom right corner. The second guard is at the computer. On the screen, there is an image of Archie and Sherlock running along, against the current of the suggested tour now and therefore making even more of a nuisance of themselves than before. Sherlock has taken Archie by the hand in order to help him keep up, and they are jostling the other visitors worse than ever.

FIRST SECURITY GUARD: Coral walk, now.

The second security guard types on the computer, and the image on the screen jumps to the next part of the Aquarium. A moment later, Sherlock and Archie run across the screen again.

FIRST SECURITY GUARD (under his breath): Gotta hate those weekend dads.

SECOND SECURITY GUARD: What's that?

FIRST SECURITY GUARD: Ignore their brats for six days of the week, and then on the one day when they can't wriggle out of it, they always overdo it. Top floor gallery in a moment. (He grabs his radio from the desk.) Right. Now let's stop that nonsense.

And they both storm out of the room to intercept the two disturbers of the peace.

A view of the upper gallery running around the foyer, and of the top section of one of the two staircases that zig-zag down to the ground floor. The staircase on this side of the hall has been cordoned off with tape, and four steps down from the top, a workman - in overalls, and with his toolbox next to him - is busy replacing a section of the rubber lining of one of the steps that has come loose, in order to remove the tripping hazard that it poses. The steps above and below are littered with his tools and instruments, rendering them impassable. Sherlock and Archie erupt onto the scene, out of the passage closest to the cordoned-off stairs. Archie is visibly out of breath, pressing his hand against a stitch in his side. Sherlock comes to an abrupt halt at the railing, and leans over to check whether their quarry is already making for the exit downstairs. But on the entire ground floor of the foyer, there is no sign of the family they are chasing.

ARCHIE (disappointed): We've lost them.

SHERLOCK: No. Impossible. Unless they ran, which they had no reason to do.

ARCHIE: But then where are they?

Sherlock squeezes his eyes shut for a moment. In his mind, he flashes back to the image of the toddler in the pushchair, squirming and whining in his seat, clearly physically uncomfortable. Sherlock's nostrils twitch, as if at the memory of a smell, and he opens his eyes.

SHERLOCK (rapidly): Nappy change. Where's the floor plan?

ARCHIE: What?

SHERLOCK (holding out his hand, impatiently): The floor plan!

ARCHIE (with a shrug): I think we left it in the turtle hall.

Sherlock looks displeased for a moment, but then closes his eyes again. Before his mind's eye appears the floor plan of the entire London Aquarium, complete with the symbols for the facilities, and one little green dot (next to the upper floor toilets) is blinking. Archie tugs at Sherlock's sleeve.

ARCHIE: Look!

SHERLOCK (opening his eyes): We'll wait for them to get out of the lift downstairs.

ARCHIE (urgently): No, look! Are those security?

SHERLOCK: Where?

He follows Archie's pointing finger with his eyes. The two security guards that we saw in the CCTV room earlier are hurrying up the - still accessible - staircase on the other side of the hall, directly opposite to where Sherlock and Archie are standing. Sherlock immediately throws out his arm to keep Archie back from the railing and out of sight, but it is too late. Puffing and panting, the security guard in front turns on the first landing and, glancing upwards, immediately spots the two troublemakers. He lets out a wordless cry of mixed exasperation and triumph and redoubles his efforts to negotiate the stairs as quickly as he can, his colleague following right on his heels. Archie turns as if to run and meet them. At the last moment, Sherlock grabs him by the shoulder to keep him back.

ARCHIE (confused): Oi, what? They can help us catch that sneaking thief!

SHERLOCK (drily): No. They're out to catch a little rowdy who knocks down granddads.

ARCHIE (wide-eyed): What?

He looks back and forth between the security guards - now on the last section of the staircase, almost on the top floor - and Sherlock.

ARCHIE (desperate): What do we do?

SHERLOCK: Wait.

ARCHIE: What?

The two security guards have reached the top floor gallery, at the opposite end from where Sherlock and Archie are standing.

SHERLOCK (very quickly): And now do exactly what I tell you, alright?

Archie's eyes are fixed on the doom that comes hurrying towards them along the gallery, cutting off their retreat.

ARCHIE (in a trembling voice): Alright.

Sherlock waits a moment longer, until the security guards have rounded the first corner of the gallery and are almost at the midpoint between the two staircases, equidistant from both. Then, without warning, he puts one hand on the metal railing and vaults over it in a single, smooth leap, landing on the closed-off stairs eight feet below, beneath the – rather shocked - workman and his tools. He swivels around towards Archie and opens his arms wide.

SHERLOCK: Jump!

With a last frightened glance at the security men - they have stopped dead, their mouths open in disbelief – Archie scrambles across the railing and, with reckless abandon, hurls himself down into Sherlock's arms. Sherlock catches him neatly and puts him on his feet, then without another word takes his hand and bounds down the rest of the staircase with him, three or even four steps at a time. They come out on the ground floor, and - still running at top speed - cross it, Sherlock making straight for the passage that branches off the foyer and leads to the lift. The two security guards on the gallery above exchange an appalled look.

FIRST SECURITY GUARD: That didn't happen, did it?

The second security guard merely shakes his head. They are about to cover the remaining few yards to the staircase to resume their pursuit, when they suddenly find their way blocked by Miss Manning the schoolteacher, holding the little red-haired girl by the hand and looking determined to see justice served.

SCHOOLTEACHER: Excuse me, but we think someone has stolen Pauline's purse from her backpack, and the thieves may still be in the building. Could you please -

The security guards exchange another look.

FIRST SECURITY GUARD (through gritted teeth): Well, that explains a lot.

SECOND SECURITY GUARD (with a grim nod): Right you are.

In the passage on the ground floor, Sherlock and Archie have taken up their station directly in front of the lift, facing its closed doors. They stand side by side, Sherlock perfectly calm and composed, Archie still slightly out of breath and almost too antsy to keep still. He looks nervously over his shoulder, but there is no-one approaching them from the direction of the foyer. The display above the lift flashes its signal that the lift is about to descend. Archie braces himself and puts his hands behind his back in an exact imitation of Sherlock's own pose. Sherlock glances at him sideways with amused approval.

SHERLOCK (out of the corner of his mouth): Chin up, Archie.

ARCHIE (ditto): Why?

SHERLOCK (in a conspiratorial whisper): Makes you look taller.

In ludicrous unison, they both straighten up and raise their chins, just as the doors of the lift slide open to emit the posh family with the thieving oldest son. The mother, not taking the slightest notice of Sherlock and Archie, steers the pushchair with the - now quiet - toddler out of the lift. Her older son and the au pair girl with the pink twins follow. Sherlock and Archie - blocking their way to the exit - don't move.

MOTHER (annoyed): Excuse me, please?

SHERLOCK (coolly): What, from your duties as a parent?

The mother stands dumbstruck. The doors of the now empty lift close, the small ping echoing in the silence.

MOTHER (recovering, almost aggressively): Excuse me, please?

SHERLOCK: Yes, it'd be nice if it was that easy, wouldn't it? But unfortunately, as far as I'm aware, parents are still expected to control their children, teach them the difference between right and wrong, and stop them committing crimes.

MOTHER: What are you talking about?

SHERLOCK: Yes, alright, I agree with you that your son here (jerking his head at her oldest child) is inexorably bound to end up as a puffed-up, self-righteous bully, just like the one you're married to. But that doesn't excuse you from at least trying to instil some sense of what's right and what isn't into him. It may only delay the inevitable for a couple of years, but that alone is well worth the effort. For example, it would spare you disagreeable scenes like this one.

The mother gasps in indignation, searching for the right words to counter such insolence, but finding none.

SHERLOCK (ignoring her, to Archie): Should we get down to business now, do you think?

Archie looks up at Sherlock and nods, intrigued.

SHERLOCK: Your turn, then.

ARCHIE: Oh.

He looks very nervous for a moment, but then takes a deep breath and steps forward to face the blonde boy. They are exactly of a height. Archie fixes the boy with the sternest look he can manage.

ARCHIE: Give it back.

BOY (with an incredulous laugh): What?

ARCHIE (unfazed): You stole a purse. In the turtle hall. From that backpack. Now give it back.

MOTHER: What?

The boy starts to grin. Archie, unsettled, glances at Sherlock for support. Sherlock gives him an encouraging smile, but offers no further advice. Archie turns back towards the boy.

ARCHIE (firmly): Don't try and be funny. It's a crime, we know you did it, and now you give it back, or – (He glances up at Sherlock again. Sherlock nods.) – or we'll make you.

SHERLOCK: No, that's a bit over the top.

ARCHIE (quickly): - or you'll regret it.

SHERLOCK: Much better.

MOTHER (to Sherlock, massively irritated): Are you -

At this moment, the two security guards come striding round the corner into the passage, the schoolteacher and her pupil tagging along in their wake.

FIRST SECURITY GUARD (loudly, in a tone of authority): So, what's going on here?

They reach the little group by the lift, looking extremely displeased.

FIRST SECURITY GUARD (to Sherlock): What exactly do you think you're -

SHERLOCK: - doing? Your job, actually. (He half-turns towards the posh family again, as if to make the introductions.) This young man here has something in the left hand pocket of his jacket that he would like to return to the charming little miss that you've been so kind as to bring along to identify her property.

FIRST SECURITY GUARD (with a frown): What?

The boy turns pale, then blushes furiously, and his hand inadvertently goes to his left pocket. He glances up at his mother, but she doesn't notice.

MOTHER (to the security guards, in a tone of deepest indignation): I'm not sure whether it's their idea of a joke, but this man and his boy here are accusing my son of having stolen a purse!

SHERLOCK: Exactly. In the turtle hall, at precisely twenty-two minutes after four, from the red and orange backpack belonging to –

He gives the schoolgirl a questioning look.

SCHOOLGIRL (in a voice trembling with a mixture of embarrassment and excitement): Pauline.

SHERLOCK: - Pauline. (With a nod at Archie) My colleague here and I will be happy to attest that -

SCHOOLTEACHER (her eyes going back and forth between Archie and Sherlock, surprised): No, wait, did you see him take it?

ARCHIE (ready to burst with pride): No, Miss, we've deduced it.

Sherlock smiles. The security guards exchange a puzzled look.

SHERLOCK (to the security guards): And before you go to the trouble of checking, I might as well tell you that the crucial half-minute in which the theft took place miraculously happens not to have been caught on camera. So if, in the future, you would prefer not to have to rely on the vigilance of your visitors to keep this place clear of petty crime, you would be well advised not the meddle with the default transmission sequence of your CCTV system for the purpose of your personal entertainment. Not to mention how unhappy the management will be when they hear of that. (Generously) Well, not from me. But as long as this place is still fitted with an antediluvian camera system that actually clicks and hums when it starts and stops transmitting, don't be surprised when people start taking advantage of your negligence. (To Archie, while the security guards stare at each other, stunned into speechlessness) And now, I think, we'll leave the two gentlemen here to figure all of that out on their own. We should really not keep Pauline waiting any longer.

Archie nods and, with an imperious gesture worthy of his idol, faces the other boy again and holds out his hand. The boy glances up at his mother, who looks back at him with a completely blank face, offering no support. He hesitates, very uncomfortable with everyone's eyes on him. Then finally, with a pout, he digs his hand into his pocket and takes out a small red purse with a Hello Kitty design on it. Pauline gives a little gasp, recognising it for her own. Archie snatches the purse out of the boy's hand, shooting him a last look of utter contempt, then turns and hands it to Pauline, who receives it with a smile, her pretty little freckled face glowing with admiration. Archie returns her smile tentatively, and seems to be on the verge of saying something, when Sherlock, rather loudly, clears his throat, arresting everybody's attention. He turns towards the boy's mother and positively startles her by offering her his hand.

SHERLOCK (breezily): Well, thank you for providing an excellent introductory case. It's been a real pleasure. (The mother stares at him, thunderstruck.) We'll leave you to sort out the unpleasant details among yourselves now. Scolding won't help, though. Just try a little more genuine, undivided attention for a change, that would go a long way. (He looks up and down her – very shapely – figure with a derisive curl of his lip.) Make sure you don't spend more time with your personal trainer than with your kids every day. (With a glance at her carefully manicured hands) Maybe get your nails done no more than once a week. (His eyes travelling further down, to her high heeled shoes) Order your outfits online, when the kids are asleep, and minimise those shopping trips when they'd rather be at the playground with you. (Generously) Don't cut back on your charity commitments, though. It would be unfair to make the poor devils of this world suffer just because you're too busy rediscovering the joys of proper parenting. (He gives her a glaringly false smile, then abruptly turns back to Archie, the smile already switched off again.) Come on. We're done here.

And without a second glance at either the mother and her ill-bred boy, or the security guards, or even Pauline and her teacher, he strides away towards the exit, Archie at his side, leaving all the others behind in an astounded silence.

FIRST SECURITY GUARD (after a moment, grabbing his colleague by the arm): Nick, I think I've just remembered -

But Sherlock and Archie are already out of sight, through the hall and ticket barriers, and out into the bright sunshine outside the County Hall, Sherlock in front, Archie jogging after him to keep up. He keeps looking back over his shoulder, clearly not yet ready to regard the case as concluded.

ARCHIE (complaining): But I wanted to see him arrested!

SHERLOCK: Nonsense, he's not going to be arrested. (He stops and turns to give Archie the chance to catch up.) His dad is going to call the manager tonight, and they'll agree on a certain sum of money being given in donation to the Aquarium, in return for that incident being conveniently forgotten, and all that will remain of our efforts is that family's name in golden letters on the plaque in the entrance hall where they thank their sponsors. It ends like that more often than not, so better get used to the idea.

Archie looks severely disappointed.

SHERLOCK (gravely): Besides, Archie, it isn't good manners to gloat over a fallen enemy.

At this, Archie looks up at Sherlock with a small, satisfied smirk. Sherlock returns it, their expressions almost uncannily similar.

SHERLOCK: Yeah, I always find that hard, too.

Archie smiles. They continue walking, but after a moment, another shadow seems to pass over Archie's face. He slows down to an ambling speed, as if hesitating to put more distance between himself and the Aquarium.

ARCHIE (a little wistfully): But I'd have liked -

SHERLOCK (cutting him off, curtly): Yes, I know. Better this way, trust me. Never a good idea, to mix business and pleasure.

He strides on. Archie, left with no choice but to follow him, does so rather unwillingly.

ARCHIE (still protesting): But John's your best friend, and you work together, too.

SHERLOCK: I work with him, yes. God forbid that I should ever work for him.

Archie looks unconvinced, but then, for the time being at least, seems to resign himself to the necessity of professional discretion. They walk on across the square, Sherlock apparently making arrow-straight for a particular destination.

ARCHIE (recovering his spirits, skipping along at Sherlock's side): What do we do now?

SHERLOCK: Now we're going to treat ourselves to the biggest ice-creams that are served in that café over there.

He points.

ARCHIE: What, you too?

SHERLOCK (with a frown): Sure. Why not?

ARCHIE (very seriously): Aren't you worried about getting fat?

SHERLOCK (amused): Not today.

A few minutes later, Sherlock and Archie are seated at a table outside a café across the road from the County Hall. They both have huge cups of ice-cream in front of them – very elaborate compositions of at least three different flavours and complete with little paper umbrellas and chocolate flakes. Sherlock has already demolished more than half of his. Archie has made a good start, too, but has now taken to toying with it rather than eating. He seems to be deep in thought again, a little vertical crease between his eyebrows. After a moment, he looks up from his ice-cream and puts down his spoon.

ARCHIE (with absolute, almost touching faith): You can do anything, right?

SHERLOCK (with a confident grin): Try me.

ARCHIE: Can you bring back my dad?

Silence. The grin slowly fades from Sherlock's face, leaving it perfectly blank for a moment. Then he inhales audibly, opens his mouth – and closes it again, lost for words.

Inside a London bus. Sherlock and Archie are sitting side by side at the back of the bus, Archie slumped in the window seat, leaning against Sherlock, deep in an exhausted sleep, his head lolling at every start and stop. With his left arm, he clutches a huge, grey plush shark, complete with red gaping mouth and white rows of teeth, almost half his own length, to his chest. Sherlock, not entirely comfortable with the seating and sleeping arrangements but apparently at a loss how to alter them without waking his little friend, alternates between glancing down at Archie to make sure he's fine, and looking out of the window as the bus rumbles along on its way to Archie's home. Then the phone in his pocket buzzes a text alert. With a few careful contortions, he manages to fish it out. On the screen, the message reads:

"Are you thinking of me, at least? J"

Sherlock rapidly types his reply -

"No. I'm thinking of children. SH"

- and sends it off. Not half a minute later, the next one arrives.

"Sherlock Holmes, you're a bad man. ;-)"

Sherlock looks out of the window for a moment. Then he types -

"If you knew, Janine. If you knew."

- and then, with a wry little smile, hits "delete".

THE END

February 2015