Just a little one-shot set sometime between 4x01 and 4x02.

Tony Hill always does the unexpected. It's one of the first things Alex Fielding learns when she first joins the Bradfield police force. He comes barging in on crime scenes where he is neither invited nor wanted, throws around the wildest theories and doesn't know when he should back off. And it's annoying Alex, because she doesn't need a head doctor to help her figure out who's committed the crimes she is supposed to be investigating. It annoys her even more because Tony has the tendency of being right. And she doesn't want him to be. The way she's heard it her predecessor, DCI Carol Jordan, relied on his advice too much at times and Alex is by no means planning to do the same. She'll solve her own crimes.

In the end she doesn't even manage to maintain that attitude throughout her first case with Bradfield CID and she ends up relying on Tony Hill to help her solve it and get to the abducted girl in time. She supposes she should be angry with herself for not being able to do it all by herself, by relying on the tried and tested ways of plain old police work, but actually she's just more relieved that the case has been solved. That is what her job is all about after all.

And when it comes to the seriously disturbed murderous minds within her jurisdiction, she would be a fool not to use the one man who always seems to know what is going on inside the heads of the killers they're looking for. Their motives are often far beyond Alex's comprehension, but Dr Hill always seems to know. In fact, Alex finds it mildly alarming that sometimes he seems to understand the killers better than the victims. The first time he suddenly started to use the first perspective when relaying the killer's mind and motives, she did a step back in shock. Fortunately it took her all of five seconds to realise that Tony was in fact not the killer and that this was apparently the way he worked, even if it was a bit frightening when first confronted with, and Tony himself didn't even notice her reaction, he was that caught up in his own world.

Kevin did notice though and he remarks on it when the doctor has left. Alex's head is still reeling from the mass of information he's poured out over her head, never mind the way he did relay aforementioned information. 'Is he always like this?' she inquires.

She gets a nod for her troubles. 'Most days, guv.'

There is a great many things Alex has still to learn. At least with Dr Hill around, life at the police station is far from boring. Tony barges in at the most unexpected times, seems always three steps ahead of the rest of them and more often than not involves himself in a case, after which Alex usually invites him to help out. It's easier that way and she's learned from her first case that trying to exclude the psychologist from a case – with trying being the operative word – will not only lead to a lot of frustration, but it is also absolutely useless; in the end he'll involve himself anyway.

Before her second month in Bradfield has passed, she finds herself wishing for a manual that instructs her how to deal with Tony Hill. If there was one, she'd have bought it already. Maybe it would tell her how to handle Dr Hill's more strange actions and habits. And he has them, weird habits, and plenty of them too. The habit to take that plastic blue bag with him everywhere for instance. Half of the time he doesn't even use it; just brings it into the station, leaves it on someone's desk for the day and collects it again when he leaves. But if that would be as weird as he got, she would be all right with it; there are worse faults. But he also fades in and out of conversations at times. All of a sudden it's as if he's not really there anymore and then suddenly he jumps in again with something completely unrelated to the things they were actually discussing. His rambling is another thing; sometimes he's going so fast that she can barely make out the words, never mind that she actually understands what on earth he is going on about. The phone calls in the middle of the night stop surprising her after the third time he's done it. Tony's clearly an insomniac when there's a case to be solved, incapable of doing what she does at night: sleeping.

But she learns and she accepts, because his habits are a small price to pay for the insights he has to offer on the cases she's working on. And the rest of the team has clearly gotten used to him and his mannerisms, so as their leader, she could hardly do anything else. As long as the killers get caught, Alex doesn't care much about the how and who helps her to catch them. It's the result that counts.

That does however not mean that he's allowed to get away with everything. She does draw the line somewhere. And she draws it when he comes round to her house in the middle of the night.

It's true, it is a difficult case they're working on and it's so confusing that Alex's temper is dangerously close to snapping. Kids keep on disappearing, their lifeless bodies turning up in school playgrounds and parks, and Alex and her team are not one step closer to finding out who's making them disappear than they were when the first child went missing. The list of possible suspects is long enough, but it's finding out which one of them it is – whether it is even one of the persons on the list to begin with – that provides them with a lot of trouble. Tony has a theory and he's certain of it, but his suspect has a very strong alibi for two of the three disappearances, which makes him the most unlikely suspect of the whole bunch in Alex's book. So she needed a break and went home at five to spend some much-needed time with Ben. She goes to bed not long after her son; she's exhausted and maybe an early night is exactly what she needs. Things may look better in the morning.

And she sleeps well and deep. At some point she thinks she hears a phone somewhere, but the noise stops after a while, before she's even fully awake and so she drifts back to sleep, thinking she might even have imagined the sound, only to be woken by another sound five seconds later, or that is what it feels like anyway. This time the noise is insistent and Alex finds herself being dragged back to the waking world quite forcefully. It's dark in her room, except for the red numbers on her alarm clock, telling her it's only a few minutes past three in the morning. Who on earth would want to be awake at that time?

Alex's brain is slow, but eventually it starts to dawn on her that that noise she's hearing is the doorbell of her own front door. Someone is ringing her doorbell at three am. Years of experience in police work tell Alex that someone at the door at such a time usually only means one thing: trouble. She gets called at three in the morning because someone somewhere committed a murder and she's needed at the crime scene. Apparently there's no such thing as committing a murder during office hours. But what is strange is that they didn't phone her, as they usually do.

Never mind all of that now. If they keep pressing that bell like they're currently doing, they're going to wake Ben and he has school in the morning, so he'll need his rest. That is, of course, provided he isn't awake already. That bell could wake the dead, which might not be such a horrible prospect if it could bring those murdered children back to life, she reflects.

Alex grabs her bathrobe and leaves the room. The noise is even louder now, but that is not what catches the DI's attention first. Ben is standing in the corridor, yawning. 'Who's that?'

'I don't know,' Alex says. 'Why don't you go back to bed and I'll tell you in the morning? Come on, off you go.' If she's to hurry off to a crime scene, she must have someone to look after Ben until she's back. There's a number of people she could call, but none of them will be available in the middle of the night.

The person in front of the door rings again. 'Coming!' she calls down and at least the insistent ringing stops. 'Off to bed you go,' she tells her son, who's still lingering in the doorway. 'You've got school tomorrow.' Ben is like every other boy his age; infinitely curious and not very likely to listen to her when there's a mystery to be solved, but there's nothing else for it. She can hardly leave her visitor waiting, even though it's hardly going to be a social call.

Well, at least she's right about that, even if she's wrong about the identity of the person she had expected to be there. It's not Kevin or Paula. Instead she finds herself looking at an altogether too familiar blue plastic bag and the psychologist who's dragging that thing here, there and everywhere with him. 'Tony,' she acknowledges quite unnecessarily, but what he is doing here is beyond her. 'What…?'

He doesn't give her the time to finish. 'I was wrong.'

It takes her by surprise. 'Sorry?'

She doubts he even heard her; he just keeps on going. 'But you were wrong as well, Alex. We were both right.' He sounds as if this should be obvious to her and while Alex realises he's probably talking about the case, she has no idea what aspect of it in particular he is referring to. And it certainly does not explain what he is doing on her doorstep at this time of night.

'Tony, what are you doing here?' Alex tries, and fails, not to sound too irritated.

It doesn't register on the mind of one of the most intelligent men to walk the earth though. 'You weren't answering your phone,' he replies, as if that explains it all, which it doesn't as far as DI Fielding is concerned. But before she can even try and get a word in, he's already off again, launching into an explanation Alex hasn't asked for. 'It's twins,' he says, excitement and triumph obvious in his voice. 'Identical twins. James McKenzie's alibi was right, because he wasn't there at the crime scene, not at the first and third murders. He was committing the second murder though.'

It really is far too early – or late, depending on one's perspective – for this and Alex isn't a morning person, especially not when she has been dragged out of bed in the middle of the night. Actually, it feels quite surreal to discuss triple murder on her doorstep at three am. It must be the most bizarre conversation she's ever had and with two months of knowing Tony Hill under her belt, that is saying something. 'Tony…'

Once again, he takes absolutely no notice. 'I was wrong about this not being a couple, and right too. They're not committing the murders together. One provides an alibi while the other abducts and kills the child. And they do push one another to go further, which is why we've seen escalation at the last murder.'

Alex finds it hard to discuss brutal murder on children during daytime, but she finds she likes it even less when it happens at night-time. 'Dr Hill!'

That seems to snap him out of his full explanation of what was happening. He blinks and looks at her. 'Oh,' he merely says when he realises what it all means. 'You were sleeping?'

How could such a clever men be so dim every now and then. 'Yes, I was.' The irritation seeps through in her voice. 'It's three in the morning, Tony. Most people sleep then.' Most people clearly doesn't apply to Tony Hill. 'I'm not even sure how you got my home address.' She hasn't given it to him.

'Oh, Kevin knew,' he replies as he's checking his watch, establishing for himself that it's a quarter past three by now. 'Is it really that late already? I'm sorry.' He sounds it, but it doesn't change the fact that he called her out of bed. And Ben as well.

Speaking of which, she hears her son's voice. 'Who are you?' Ben is standing on top of the stairs, peeking down curiously. So much for going straight back to bed. Well, she was not expecting it to begin with.

Tony looks back, just as curiously, until he connects the dots, that is. 'Ah,' is the only thing that comes out of his mouth at first, but then he answers the question that has been posed to him. 'I'm Tony,' he says.

'I'm Ben,' is the reply. 'Why are you here?'

'I'm a friend of your mother's,' Tony says. Alex however is not sure that he can be called a friend already, especially not after this little incident. Tony catches the disapproving stare and adds: 'Although I don't think she likes me very much right now.'

His social skills are almost non-existent at times, but right now he is absolutely right. 'Ben, go back to bed,' she says sternly. 'You've got school in the morning.'

She gets a dutiful 'Yes, mum' for her troubles and then Ben does pack himself back off to bed. He looks disappointed though, as if he knows he's missing all the fun. Alex isn't sure though there is much fun to be found, not with a murder case.

'Come in,' she says. If her previous experience with Dr Hill is any indication, he won't leave until he's told her all he came here to tell. And she's awake now anyway. She might as well listen to what he has to say and with any luck they can get a credible lead out of it.

Tony does as he's told, looking around the hallway as he does so. 'You're divorced.' Alex wonders if that is a question of the stating of a fact. She strongly suspects the latter, but the majority of her mind is wondering how on earth he knows.

'How…?' she asks.

Tony shrugs. 'There's no evidence of any adult male present,' he comments. 'You do have a son.' He catches her stern look. 'Oh, come on, Alex, it isn't like you to have a child without being in a steady, long-term relationship. Wouldn't be the responsible thing to do.' He walks on to the living room and therefore completely misses out on the icy stare the owner of the house is unleashing on his back. It annoys Alex enormously that he apparently reads her like a book, but she still can't get the measure of him.

'You can't go knocking on people's doors in the middle of the night,' she tells him, shutting the front door behind her and following him into the living room. Tony has taken the liberty of monopolising her table and is spreading out papers on it, his mind already back on the case. 'What were you doing up so late anyway? Coffee?' If she's going to have this absurd session anyway, she might as well take some coffee to help her through it.

Apparently she has distracted him. 'What? Oh, yes, please.' Alex waits for the answer to her other question. 'I was awake, mulling over the case. Sorry, Alex, I didn't know it was that late already.'

She fixes him with the same stare she uses on Ben when he's been up to mischief. 'Don't do it again,' she warns him. 'Unless it's life-threatening, it can wait till morning.'

He at least has the decency to look ashamed.

'Well, let's hear it then,' Alex invites.

It's the cue he's been waiting for and as he makes his case, Alex has to admit that he truly does know what he's doing. He is in the possession of a brilliant mind and slowly the whole case starts to become clear to her. He's so caught up in his own reasoning that, quite by accident, she's convinced, he calls her Carol. He doesn't even seem to notice that he's doing it, but it has Alex thinking. Did he do this kind of late-night visits with her predecessor as well and did she appreciate it any better than Alex does? From the way he talks she can deduct that this is something he's doing often. She thinks it better not to ask though. As far as she is able to read Tony, she thinks he was close to devastated when he learned that Carol had gone. By now she's heard enough snippets of gossip to make an educated guess that there may have been more between Tony and DCI Jordan than just a working relationship, but it is all so vague and undefined that she can't really make anything of it. And she knows better than to ask; she doesn't want to put her finger on the sore spot.

When it's almost five am Tony's finally done explaining and Alex is done asking questions. The case looks quite strong now and Alex won't deny that is a relief. 'We'll bring him in for questioning in the morning,' she promises. 'Get some sleep.'

Tony arches an eyebrow. 'And will you be doing the same?'

'None of your business,' she reminds him. 'Good night, Tony.'

He smiles back, plastic bag in one hand, car keys in the other. 'Night, Alex.'

'This is the last time!' she calls at him when he's turned his back. 'Next time it can wait.'

He says 'Of course' and is gone. He remembers his promise all of three weeks, when he's standing on the doorstep only slightly earlier than last time – two am – to run a theory he's just come up with past her. Alex just favours him with a stern look and lets him in. She might as well accept the inevitable.

I hope you liked it. If there's anyone still reading in this fandom, please review? I'd love to hear what you think.