I know that a) this is daft and b) there are probably lots of plot holes; however, I wanted to write the trio together on September 1st and ... this is what my brain came up with ...

"Books?"

"Check."

"Cauldron?"

"Check."

"Wand?"

"Check." Teddy heaved a sigh, and Harry shot him a sympathetic look over his grandmother's shoulder. "Honestly, Gran, I've got everything."

Andromeda sniffed. "Well, you can always write to me if you find you've forgotten anything. Dora –"

Teddy glanced up eagerly at the mention of his mother.

"Did she forget stuff?"

"Constantly," said Andromeda.

It had taken some years for her to be able to speak about her daughter in this way, but Harry saw how much Teddy loved it when she did; every little detail was a precious gem of information about the mother he'd never known.

He looked pleased to learn that she had been forgetful; for all his reassurances to his grandmother, he would, Harry was sure, have forgotten to pack something in the trunk Harry had just loaded onto the train, clearly marked E.R. LUPIN in Andromeda's firm hand.

Platform 9¾ hadn't changed much in the years since Harry had last been there, coming to collect Ginny after her last term at Hogwarts ten years earlier. All around were families, parents fussing over their children, some taller, bolder and keen to reunite with their friends; others nervous-looking eleven year olds, jittery with anticipation, unwilling to venture far away from their family now the moment of departure loomed. Harry flattened his fringe down as he looked around, an almost unconscious habit, though it was (as Ginny pointed out) a bit daft really: his face had been over the papers so much, people didn't just recognise him by his scar these days. His anonymity there today was hinging on the hope that most of the witches and wizards present would be focused on their children to notice him.

No sooner had he thought this than he felt – with a sinking heart – someone tap him on the shoulder. Slowly, reluctantly, he turned around.

"Oi oi," said Ron, his arm around Hermione, who was beaming. "Don't look too pleased to see us, or anything."

"Sorry," Harry said, relief flooding through him. "Thought you were … What are you two doing here?"

"Come to see Ted off, of course," said Ron, reaching out to ruffle Teddy's hair, today his natural light brown. From his pocket he pulled a distinctive Weasleys' Wizard Wheezes package, which he slipped to Teddy in a not particularly discreet manner. Andromeda pretended not to notice, and Teddy grinned widely.

"Cool!"

"Have a lovely time," said Hermione, hugging him. "Work hard –"

"And have fun," Ron chipped in, rolling his eyes at his wife.

"Work can be fun," she protested. Harry and Ron exchanged looks, but didn't say anything.

"You had better get on board," Andromeda said to her grandson, kissing him. Typically undemonstrative, Harry guessed that she would have said her proper goodbyes in private. It must, he thought, be very hard for her to put him – her only source of comfort after so much loss – on a train and wave him off for three months.

Harry bent down and grasped his godson's shoulders.

"I'll miss you, but you'll have a wonderful time," he said. "You won't mind writing to your old godfather now and then, will you?"

"I'll write every week," Teddy promised.

"I'd like that," said Harry. He hugged him tightly. "I'll be up to teach a bit before too long, so I'll see you then anyway. Don't get into trouble if you can help it …"

"You're one to talk," he heard Ron say from somewhere above.

"… but no one will be cross about a little trouble, least of all me. Be yourself, that's the most important thing, and you'll do fine." He smiled, hugged Teddy again, and – with a slight wrench at his heart – let him go. Beaming, Teddy hugged his grandmother and leapt onto the train, already waving madly. Harry waved back.

"Oh no," said a voice beside him. He glanced around at Hermione, who was frowning at a point some way down the platform. "It's that horrible cow Fenella Busby. From Witch Weekly? She's the one who writes everything about us …"

"… and she's looking right at us," finished Ron, following Hermione's gaze.

Harry swore under his breath.

"She saw us?"

"Uh … yep," Ron confirmed, starting to hustle them in the opposite direction, away from Andromeda, who had leaned forward to say something to Teddy through the train's open window. "Quick, let's –"

But what he had been about to suggest – 'go', Harry guessed – was lost in a groan as Fenella Busby, perhaps spotting their sudden unease, began striding towards them on unfeasibly long legs. There was a notepad in her hand and her eyes were narrowed in a way that indicated she was not going to let them get away easily.

They were at the other end of the platform to the barrier: they would have to pass her in order to escape that way.

"We can just Apparate though, can't we?" said Harry, slightly alarmed by the speed with which Fenella was approaching.

"Well, did you ever get your licence?" said Hermione sternly.

"That's not – I can still Apparate –"

"We can't, anyway, you can't Apparate or Disapparate from this platform –"

"What!" Harry and Ron blinked at her in disbelief. "Why not?"

"Do you really want me to explain right now?" hissed Hermione, grabbing both of their sleeves and looking around desperately, searching for a way out. "Oh God, I'm not talking to her, she's been trying to get an interview for years – she must have guessed you'd be here, but –"

"- but all three of us is a goldmine," said Ron weakly. "She must be having a field day."

"We've got to do something –"

"We need a diversion," said Harry hurriedly, thinking fast. "Hermione – what would you -?"

Without a word, Hermione pulled out her wand. There was a loud BANG as a cloud of purplish smoke enveloped their area of the platform; some people screamed, but under its cover, Harry was already tugging Ron and Hermione towards the only hiding place he could see. Swinging open the train door, they scrambled inside, ducking down at once.

Ron crept towards the window and peered out.

"The smoke's not cleared yet," he whispered. "I can't see Busby –"

Harry was distantly aware of a whistle blowing. "We just need her to look for at the other end of the platform, so we can sneak out –"

"She's such a cow!" said Hermione viciously. "I can't believe she'd show up here!"

Ron turned away from the window.

"You know, I don't know if we will be able to sneak away, she won't give up that easily."

"Well she might, if she can't see us, who'd guess that we'd hide on the train?"

There was silence for a moment. In it, Harry became suddenly aware of the train rattling in a way it had not been minutes before.

"Is it just me," said Ron slowly, "or do either of you feel like we're … moving?"

Harry leapt towards the window. Sure enough, the train was in motion: Platform 9¾ had become a blur, moving gradually out of sight.

"We're moving!" he shouted, and yanked at the door. It wouldn't open; he swung around to stare wildly at Ron and Hermione. "The door's locked!"

Hermione gasped. "It's a safety spell! They lock as soon as the train starts to move!"

"We can't open them?"

"Well – no, and anyway, if we tried to get off going this quickly –" For the train had gathered speed; the platform had slid away completely.

"It's fine," said Ron, sounding much calmer than the others. "It's fine, we'll just Disapparate."

Hermione gave a little squeak.

"No, we won't," she whispered. "You can't Apparate or Disapparate from the Hogwarts Express. It's in Hogwarts: A History –"

This time, Harry didn't bother swearing under his breath.

"So … what?" said Ron, looking from the two of them in frank disbelief. "We're stuck here? Going to Hogwarts?"

They had found an empty compartment in which to deliberate their dilemma, crouching down low to move along the corridor unseen by students (Harry thought it was best not to let Teddy know he was there), and Charmed its window not to reveal who was inside. It was, as Ron said, more than a little ridiculous. "We are parents," he hissed, as they half-crawled down the corridor. "We're nearly thirty!"

"We could ask the driver to let us off," Hermione said, tapping her chin thoughtfully. "Only if they went to the press about it, we'd never hear the end of it –"

"We could Oblivate them," Ron suggested.

Hermione pursed her lips. "Harry and I are in Magical Law Enforcement. If it got back to anyone, we could lose our jobs. And anyway … I don't like doing that."

Harry knew she was thinking of her parents, who had never quite got over the fact that their daughter had modified their memories.

He paused, then said, "is it really the worst thing if we're stuck here for a bit?"

"Yes," said Hermione at once. "Harry, weren't you listening? We have jobs, we have children –"

"You two were free enough to come to King's Cross at eleven o'clock on a Tuesday," Harry shot back. "The kids are at the Burrow, right?"

Biting her lip, Hermione nodded.

"It is my day off today, actually," Ron admitted. "I was going to get the kids and do some baking, but – I suppose …"

He looked around the compartment.

"It's quite nice being back here. Having a bit of time, just the three of us, eh?"

"But we can't just –"

"Why can't we?" Ron countered. "Hermione, you work all hours of the day, and if you're not doing that, the kids take up all our time. When was the last time we three were just together?"

Hermione, Harry was pleased to notice, looked like she was wavering.

"Besides," Ron added, "I've never ridden this train before knowing that Malfoy isn't going to come along and be a massive dick to us. Makes it much more enjoyable, don't you think?"

Harry and Hermione laughed.

"All right," Hermione conceded. "But as soon as we get to Hogsmeade, we're going home, OK?"

"No," said Ron sarcastically, "we're going to get in the boats and go and get Sorted. Yes, Hermione, we're going home."

Leaning back in his seat, watching the countryside fly past, Harry tried to think back to the last time he'd made this journey.

Sixth year, he thought. He'd had to sit with Slughorn – and (Ron was right) he had spied on Draco Malfoy and had his nose broken for his trouble. Ginny had been going out with Dean; Ron and Hermione hadn't yet admitted their feelings for each other. Dumbledore, and so many others, had been alive, Voldemort undefeated, and Harry had known nothing of what – if anything - the future might hold for him.

He looked across at Ron and Hermione, who were gently bickering about whether Ron would still fit into his old school robes, and smiled. He had missed their company. Ron was also right about that: he couldn't remember the last time they had been together, just the three of them.

"You're thinking too hard, Harry," he heard Ron say, and refocused his attention. "Want to play Exploding Snap? I reckon the trolley should be around soon, I'm starving."

"No corned beef sandwiches now," said Harry, smiling.

"Ha," said Ron. "Remember that first journey? You bought loads. I thought you were a millionaire."

"Well, you're buying this time," Harry grinned. Ron's ears went red.

"And then we met Neville - looking for his toad," he said. "And then …"

They both looked at Hermione, who turned faintly pink.

"Ah," said Ron mistily, putting an arm around her. "I remember thinking, that's the girl I'm going to marry, isn't she lovely …"

"You did not," said Hermione. "You thought I was a nightmare, if I remember correctly."

"Time is a great healer," Ron said hastily, giving her shoulders a squeeze. "All a long time ago, wasn't it?"

When the lunch trolley came – the witch looking only mildly surprised to see them, which was perhaps one of the perks of fame – you could do what you liked - Harry and Ron bought a stack of pasties, sweets and cakes, which Hermione pretended not to be interested in, then snaffled a Chocolate Frog from the pile.

"Who've you got?" Ron asked, brushing crumbs off his jumper and nodding at the card.

"Harry," she said, turning it over to read the back. Harry caught a glimpse of his own face, smiling awkwardly at the floor.

"Damn, I wanted me."

"You've got about twenty of you –"

"As if you weren't hoping you'd get yours –"

"I wasn't, actually!"

"Here, I've got you, Hermione," Harry interrupted, unwrapping his own Frog. His children were too young to put much stock in collecting the cards, but Teddy had long got used to the fact that Harry and his friends often appeared with his chocolate. Harry, on the other hand, didn't think he'd ever get used to it. He couldn't help remembering how Dumbledore had been on the first card he'd ever had. Harry's card described him as the most famous wizard in the modern world, which felt as if it was talking about someone else. He much preferred the bit that said 'In 2004 Mr. Potter married England's top-scoring Chaser Ginny Weasley. The couple have three children.'

"It's very strange, isn't it?" said Hermione, looking at her own card. "I would never have imagined that we'd be on these."

"Harry was always famous, though," Ron pointed out.

"But we weren't, were we?" She sounded pensive. "If you think about it … what if Harry had sat in someone else's compartment? What if I'd never been in the bathroom when the troll came in, and you two hadn't saved me, and the three of us weren't friends – it might have been anyone else who went along with Harry and became famous."

Ron opened his mouth to answer – or argue – but Harry got there first.

"No," he said. "It couldn't have been anyone else."

"But it could have been –"

"Oh yeah, I might have been friends with anyone else but – all the things you two did – no one else could have done those in that same way."

"Well, I don't know," said Ron uneasily. "I mean, Hermione's brilliant and all, but you know – Neville, or Dean or anyone, they could have done what – I did."

Harry shook his head impatiently. "What about the chess game?" he said sharply. "What about getting me from the Dursleys? What about all the times you risked your life – do you think just anyone would have - could have -done that?"

"But –"

"No! Don't you get it? It had to be you two, it –" Harry broke off, feeling quite overcome. "It had to be," he repeated forcefully, and he saw Ron and Hermione look at each other, and hoped that they understood.

"And," he added, quietly, "I wouldn't have wanted it to be anyone else."

There was a long silence.

"I wouldn't have, either," said Ron finally, and Hermione nodded, her eyes shining with tears.

The sky outside had darkened to a deep violet, the landscape growing wilder and bleaker as the train sped through the Highlands. Hermione had her head on Ron's shoulder as he and Harry played Exploding Snap. At one point, Harry said, "we ought to change into our robes, really," and Hermione jerked upwards in horror before remembering that they weren't actually students, which made Harry and Ron roar with laughter.

"We will be reaching Hogwarts in five minutes' time," came a voice from overhead. "Please leave your luggage on the train, it will be taken to the school separately."

A brisk wind chilled the air at Hogsmeade Station. Harry, Ron and Hermione clustered away from the masses of students, most pouring towards the carriages, apart from a cluster of first-years who were being called by an enormous figure bearing a lamp.

"All righ' there, young Ted?" Harry heard Hagrid say. He smiled to himself.

"Well, I suppose we can go now," said Hermione, shivering.

Ron was looking at Hagrid, leading the first-years away.

"It would be funny, though," he began, and Hermione said at once, "No!"

Harry, following his train of thought, broke into a grin.

"It would be funny," he said.

Hermione looked despairing.

"You can't really both be thinking –"

"Come on, no one'll notice us," Ron reasoned, "and even if they do, what a story, eh?"

Harry was laughing; Hermione sighed, which Ron seemed to take as – if not approval – then acquiescence at the very least.

"Brilliant," he said, grabbing her hand, and the three of them headed down the narrow path that led down to the lake edge.

The first-years had already got into their boats. Hagrid was about to climb into his. He glanced around as Harry, Ron and Hermione approached, and did a double-take.

"An' here I though' I'd got rid o' yeh," he said, his beetle-black eyes crinkling. "What're yeh doing here, then? Up to no good?"

"Slight mishap," Harry told him vaguely. "Perhaps best not to dwell on it."

"Believe it or not, this was the most legal way of dealing with the situation," said Ron. "Which isn't like us at all, really."

"But we thought, now we're here …"

"We did enjoy this journey the first time round, so it seemed a shame to pass up on the opportunity …"

"Hagrid might get into trouble for it, though," Hermione fretted. "We oughtn't risk that –"

"I migh', if I agreed ter it," said Hagrid. "But I didn' see yeh, did I?"

"You didn't," agreed Ron fervently, reaching up to clap him on the back. "Cheers, Hagrid."

"Didn' hear tha'," Hagrid muttered, as he climbed into his boat. Harry, Ron and Hermione waited for the fleet of first years to set off before cramming awkwardly into their own. Hermione tapped it with her wand and they followed the others across the great black lake.

"I don't remember it being this small," Ron complained.

"That's because last time you weren't six foot three."

"Can't you budge up a bit? I'm really squished –"

But they fell silent as they drew nearer to the cliff, and atop it, the castle.

To an uninformed observer, it might look as if it had not changed all in the eighteen years since Harry, Ron and Hermione had first clapped eyes on it; but they had seen it as it was after the battle, torn and crumbling in places. It had taken months and many willing hands to return it to its previous state. Harry tried to catch a glimpse of Teddy in one of the boats. His parents had died in that castle, but he hoped he would be too happy there to think about that much.

Hagrid and the first years disappeared through the opening of the cliff face; Hermione, slowing the boat down, made them linger before they too bent their heads to pass underneath the castle. When they reached the harbour, the large group had already made their way up to the castle.

Hermione fixed the two men with a stern look.

"OK, we've done that," she said. "So now we're going home."

"Right-o," said Ron. "Except – er –"

"What?"

"Well, you can't Disapparate from within the Hogwarts grounds, can you?"

Hermione's mouth fell open.

Harry, grinning at Ron, nudged her. "Come on, Hermione – don't tell us you'd forgotten that …"

"No! I just – what's your plan, then?"

"Don't have one," said Ron. "Winging it, aren't we?"

"I had an idea," said Harry. "If we got into the castle, we could Floo from one of the teachers' offices. Neville wouldn't mind." He blinked at the rather blank stares he was receiving. "What? I didn't think it was the worst idea I've ever had."

"To be fair, mate, that's not saying much," said Ron.

"What if we're seen?" Hermione hissed.

"Seen by who? Everyone'll be at the feast."

This was a good point, and once again, Hermione appeared to waver.

"Oh, all right," she said crossly. "But if we are seen –"

"Then we'll run and hide," said Harry. "That's always worked for us before, hasn't it?"

Ron chortled all the way up to the castle.

It felt quite bizarre to be walking through the front doors with Ron and Hermione at his side, but Harry could not help enjoying himself. He felt very removed from his regular life as father, husband and Head Auror. It wasn't that he would have given that up – far from the past being a simpler time, he felt that his adult life was in fact far less stressful than his adolescence had been – but to relive the best part of it – time spent with his best friends – was something quite special.

From the Great Hall came the sound of applause; the Sorting Ceremony was underway.

"Don't you want to see Teddy?" Ron asked, but Harry shook his head.

"I'll let him tell me when he writes."

He did not, as he pointed out, know exactly where Neville's office was, nor did he know where Professor Sprout's had been, assuming he'd taken it over; but Hermione thought it might be on the first floor, so they headed there.

"I just hope it's unlocked," said Ron. "I know he wouldn't mind, but it feels a bit wrong, breaking and entering."

Hermione raised her eyebrows. "It's not like we haven't done it bef-"

"Potter! Weasley! Granger!"

In that moment, as the strident and none-too-pleased voice rang out behind them, Harry felt instantly transported back to his teenage years. From the look on Ron and Hermione's faces as the three of them turned to face the Headmistress, they felt much the same. Hermione looked terrified.

Professor McGonagall's stern look swept over them.

"What is the meaning of this?" she barked.

Harry felt he ought to be the one to explain. As he launched into the story, he realised just how implausible and ridiculous it sounded. McGonagall's eyebrows travelled further and further up her forehead.

"I see," she said. "Could you not have used Ms Granger's diversion to move past this journalist and leave through the barrier?"

There was silence.

"We … didn't think of that."

"No," said McGonagall. "Clearly. And why did you not, upon reaching Hogsmeade Station, choose to Disapparate from there?"

"Er," said Ron, his ears very red. "We … we thought it would be … we wanted to ride in the boats again."

McGonagall's mouth was a very thin line. Then – so very slightly that Harry thought at first he'd imagined it – the thin lips twitched.

"As much as I would like to, I suppose I can no longer give you detention," she said. Hermione gave a squeak of relief. "Instead I suggest that you take your leave promptly. You may use Professor Longbottom's office; I will inform him later. I daresay he will find it amusing."

"Yes, Professor," said Harry. "Er – sorry."

There was no doubt about it this time: McGonagall was smiling, albeit rather exasperatedly.

"I had rather thought that your days of getting into trouble here were over," she said. "And that I might have something of a rest until your children joined the school. Might I encourage you to leave the troublemaking to them?"

Harry, Ron and Hermione exchanged glances.

"We'd better not promise anything," said Ron evasively.