The headmaster had been informed of the boys' whereabouts and the importance of their involvement had been pressed upon him, so when they reached the castle doors Pontius Filch was there waiting for them, only slightly jeering, with his three hideous and scrawny cats winding around his legs. "To yer beds," he spat (literally; phlegm seemed to shoot from the man's mouth each time he opened it) and at Sherlock's quick and biting, "Obviously," he only made a face and pulled the doors shut behind them, his arms crossing and his eyes squinted at them suspiciously.

Sherlock gave John's hand a small squeeze and let go, yawning again. "A good case," he said, his voice rough, "always puts me in mind for a nap."

"It's nearly five," John chuckled. "So I think a nap is all you'll be able to manage. I don't have class till after ten, thank God."

"Oh joy, you've rediscovered Muggle blasphemy." Sherlock shook his head and sighed, "Good night, John."

John's lips shifted into a very small smile. "Good night, Sherlock." They hesitated for a moment before Sherlock nodded and turned away, stretching his back as he walked. John watched him go, eyes trailing from the mess of dark hair down to his upturned collar and the long line of his coat, and shook his head at himself before heading up to the Gryffindor tower for a much needed kip in his dearly missed bed.

x

Herbology was torture, especially with it being mandrake season, but by lunch John had finally left his grogginess behind and entered the Great Hall with inscrutably clean hands (because, truth be told, the little buggers in the potted plants made John feel more squicky than he was willing to admit aloud) and a rumbling stomach. His feet led him automatically towards the Gryffindor table, where his friends were eyeing him curiously, but a sudden shout of "John!" stopped him in his tracks.

Just that voice was enough to make John's stomach do flip-flops. You are well and truly done for, Watson, John thought mercilessly, looking over at the Slytherin table. But it was true, and looking at Sherlock with his sleep-rumpled hair, impossibly tidy clothes, and perpetually sly grin only drove the fact home: John was a goner, he was royally wrecked, done in and made a lost cause. Nothing in the world could have stopped him changing course and falling on to the bench beside Sherlock just then, not even a parade of veelas wearing dresses made of Galleons. He was madly, irrevocably smitten with the madman beside him, and he was all too aware of how hopeless his chances were.

"Morning," the madman yawned cheerfully, and John was so caught up in his whirl of thoughts that he didn't even think to correct the boy and remind him it was early afternoon. "Sleep well?"

"Mmmf," John said, and then shaking himself, "Um, yeah. You?"

"Ugh, sleep. Boring at the best of times." Sherlock looked up at him suddenly, scrutinizing him carefully. "All right, you've got something on your mind. Out with it."

Damn. John cleared his throat and cast around for something, anything to talk about. "Oh, ah…the um, thing with your brother," he said after a moment, nearly sagging with relief when Sherlock accepted the topic with a raise of his eyebrow and a careful nibble of buttered bread. "Was all of that true?"

"Yes," Sherlock said, his mouth full. "But we musn't talk about it here. Later, though." He finished chewing and took a drink of cider before continuing, "Later we can discuss our plans." If Sherlock noticed John's sudden look of surprise, he didn't acknowledge it, instead grinning and saying, "Oh! But I have devised one plan that I think will please you."

"Oh?" John croaked, shifting in his seat.

"Mm. I've figured out what we're going to do about that Inter-House Challenge."

"Oh." That wasn't really what John had expected, and he was both relieved and disappointed to hear it. "Okay. What do you have in mind?"

"The cases, John!" Sherlock's eyes were glistening in a way John had already learned to feel wary about. "Why do anything more? We'll work whatever cases come my way this year together, and you'll write them up for your report. I'll…slap-dash together some sort of presentation for my O.W.L.; it hardly matters." Flapping his hand impatiently, he drawled, "I have absolutely no interesting in winning the cup, and I certainly don't imagine I'll get anything less than an 'O' for my efforts."

Actually, that was a pretty great idea. John liked writing, not that he'd ever mentioned as much to anyone else, and he'd hoped Sherlock would ask for his help on more cases. It seemed like a really tidy solution to a problem that had somehow slipped his mind entirely. "Brilliant," he said. "That's brilliant." Sherlock beamed at him so powerfully then that John had to look away and stare down a plate of delicatessen just to keep from making himself into a fool.

x

Sherlock wasn't at supper, but the Gryffindor table kept John occupied well enough, pummeling him was a barrage of questions that faded suddenly when a large, all-black owl swooped neatly overhead and dropped an envelope and a small pouch on the table before him. The envelope was a dark, rich chocolate brown, and when John opened it he found one small page of buttery-smooth, cream-coloured paper inside. Unfolding it, John discovered only a few short lines of neat, curling text written in silvery ink.

Baloo:

Please allow me to extend my gratitude and apologies with a small gift. To avoid incurring Mowgli's wrath, you might consider destroying this letter at once.

Sincerely indebted,

M.

John grinned at his new code-name for a long moment before suddenly remembering the little pouch and turning his attention to it at once. The pouch itself was a rich purple velvet, but once he turned out the contents into his palm the pouch fell, forgotten, to the table.

In his hand, John held two of the little shells Mycroft had used to contact his team. They really were just seashells, it seemed, but he didn't dare test them at the table. Instead he tucked them into his pocket, shivering with delight. It was almost like playing James Bond.

x

"Oi, Watson."

John looked up from where he'd been turning down his blanket to find Mike Stamford leaning in the open door of the boys' dormitory, his chubby face pink and smiling. He straightened and made a questioning noise, though the look on Mike's face was almost enough of an answer.

"Got a visitor," Mike said, and then John was sure.

Still… "Sherlock Holmes?"

"Good guess," Mike laughed. "He looks well out of place up here, I'll add."

"He's not…in the tower, is he?" John tried, and failed, to picture Sherlock in the Gryffindor common room.

"Merlin, no. He's out in the hall."

They shared a laugh, and Mike shook his head as they went down the stairs together. "Wouldn't have guessed it before, but you know? Something about the two of you being friends makes sense to me."

"Don't get all soppy on me, Mike," John joked, rolling his eyes. The bigger boy chuckled heartily before wandering back over to the heated gobstones tourney taking place in front of the roaring fire, and John steeled himself before stepping through the portrait and out into the hall.

"I've been out here for ages," Sherlock complained immediately. He looked tired but lovely, his odd-coloured eyes hooded with drowsiness. "Suppose there were an actual emergency?"

"I've got just the solution," John smiled, remembering Mycroft's gift. He fished one of the shells out of his pocket and pressed it into Sherlock's waiting hand.

Sherlock tutted. "Mycroft, the weasel." Looking up at John, he said, "Don't let him charm you away with gifts and flattery, John. You're on my side."

John flushed a little but nodded. "No worries there, mate," he said, and instantly regretted saying. Clearing his throat, he added, "Anyway, I've got one too. So…"

"No, this is perfect," Sherlock said with a little, crooked smile. "I've been elaborately planning how to talk to you privately all day. I devised a code, and system involving the fireplaces, and this thing with a set of Exploding Snaps and a pair of sturdy owls- anyway, this is much simpler. You don't mind me hanging on to it?"

"Not a bit."

"Excellent. Then I'll be in contact. Good night, John." Glancing surreptitiously down the empty corridors, Sherlock seemed suddenly awkward. "I…well, good night." He started to walk away and John reached out automatically, grabbing his hand.

"Sherlock…" There didn't seem to be enough air this high up in the castle. Sherlock's eyes were focused on John's with an intensity that John wasn't sure how to interpret. Feeling foolish, he let Sherlock's hand go and rubbed at his neck. "Um. Good night."

There was a long pause, and then Sherlock nodded and trotted off down the hall with nothing less than his usual grace, leaving John to bumble speechlessly back up to his bed.

x

"Holmes to Watson, over."

John groaned and blinked at his bedside table blearily as Sherlock's voice, small but clear, said, "Holmes to Watson, do you read? Over." Letting out a long breath, John scooped the little shell up and brought it to his lips, whispering, "Watson here. Do you have any idea what time it is? Over."

"Oh-four-sixteen. Over."

Christ. John rolled his eyes. "That was rhetorical. What do you want? Over."

A pause, and then, "Were you sleeping? Over."

"At not quite dawn?" John yawned and rubbed his eyes. "Amazingly, yes. Yes, I was. Over."

"Oh." Sherlock sounded almost contrite. "Well, now you're awake. Do you want to me to explain that conversation with my brother or not? Over."

Despite the early hour, John found he was intrigued. "Give me a few minutes. I've got to pop to the loo. Over."

"Bring the shell with you. Over."

"Sherlock!" John had to cover his mouth to stifle a giggle. "No. That's…no. Over."

"I have no interest in listening to you urinate," Sherlock drawled, and John could practically hear him rolling his eyes. "But I've only just remembered that you share a room and it wouldn't do for any of this to be overheard. Over."

"Fine, okay. I'll call for you in a couple of minutes. Over and out." John eased out of bed and yanked on his dressing gown as he toed on his slippers, heaving a mighty yawn as he shuffled down the stairs. There was a separate annex that held both a girls' and boys' lav just off the common room, for times when the students weren't meant to be out in the corridors. John tended to his morning routine with a touch more energy than usual before sinking down onto one of the cool marble sinks and pulling the shell out of his pocket again. "All right. I'm back. Over."

"You're supposed to say 'Watson to Holmes'. It's good protocol. Over."

John smirked at Sherlock's tone, the mix of petulance and amusement clear even through the tiny shell. "I suppose we'll be using the phonetic alphabet as well. Over."

"Not a bad idea, John! Do you know it? Over."

"Learned it in scouts. Over."

"Muggles and their strange rituals. Which brings us to our topic. Over."

John's smile faded. "Yeah. How did you know all of that? Over."

"The cabbie's last word was 'professor'. Someone tried to break into the headmaster's potion stores. Do you really think that's a coincidence? Over."

"No, I suppose not." John rubbed his jaw absently, musing. "But you said it was useless. The cabbie telling you 'professor'. Threw a little tiff if I recall correctly. Over."

"That was hardly a tiff, John. We'll need to work on your memory. But no, it was useless." Sherlock sighed. "I already suspected the professors, of course. I said that, remember? It could have been anyone with access to the headmaster's office." After a pause, he added, "Over."

John shrugged at his own reflection. "Narrowed the field at least. Over."

"The professors would have been my first points of investigation, obviously," Sherlock snorted. "Now, if he'd given me a name…" He sighed. "Still. This will be an interesting challenge. Over."

Taking something of a risk, John asked, "What are we going to do? Over."

There was a smile in Sherlock's voice as he answered, "I have no idea." After a moment, he said, "But you should go back to bed. I'll think on it for a bit and we can talk it over later. Over."

"Oh, you mean you'll actually keep me up to date this time? Over." John's voice was more teasing than stroppy, but he still wanted some form of reassurance.

"I have every intention of doing so," Sherlock answered cheerily. It wasn't a firm 'yes', but John suspected that was the best he was going to get, so he didn't argue when Sherlock said, "Now go to bed. I'd forgotten ordinary people sleep, and I assume you need it. Over and out."

"Yes, sir," John smiled. "Over and out." He looked fondly at the little shell and tucked it in his pocket before sighing at his own ridiculous expression. "You're done for, mate," he said to himself, shaking his head. "Well and truly."

A/N: Thanks for reading! Any inaccuracies are due to me being too lazy to do proper research. Legwork, ugh. I should add that the entry for lobalugs is actually quite small in Fantastic Beasts and Where to Find Them, and thus I've embellished upon the idea pretty thoroughly. Here's hoping J.K. doesn't come out with something on Pottermore in a few months/years/eons that completely ruins my story. Also any dialogue lifted from ASiP belongs to Moffat and Godtiss and blah blah blah, you know the rest. Stay tuned for the sequel, "The Blind Goblin," in which John visits Gringott's for the first time, gets a beard- ahem, girlfriend- and learns a little about Sherlock's past (as well as all that smuggling jazz).