John Watson was not having a very good day.

For one thing, he'd been up half the night with his new "colleague" and the boy he was meant to be mentoring, Sherlock Holmes, the younger boy having spent the entire evening and most of the night teaching John the basics of fencing in the Room of Requirement. Then John had slept through breakfast and Herbology, tripped on his shoelaces going down the stairs, and broken the strap on his satchel, thus spewing his books all over the corridor where they were gleefully trampled by a pack of third-year Slytherin girls.

For another thing, this potion was not going as planned.

John glared down at his cauldron, eyeing the viscous brown liquid that burbled within unhappily. It was meant to be a sort of golden mist, but something had gone wrong along the way and… Sighing, John scooped up a handful of powdered goat's liver and flung it into the cauldron, leaning away from the fumes that hissed out and wrinkling his nose with distaste at the smell it emitted. No way was it supposed to smell like that, he was sure. Daring a glance at the Potions professor, who was kindly praising one of the Ravenclaw boys across the room, John held his breath and gave the mix three counter-clockwise swirls and a flick of his wand. For a long moment, nothing happened at all. John let out his breath and peered into the cauldron, mentally cursing the cheap second-hand instrument and its disgusting contents.

Then, the potion exploded.

x

Having fallen into something of a routine in the past few months, John went straightaway from supper to the dungeons that housed the Slytherin common room. He'd washed up as best as he could manage after Potions, but judging from the odd looks he garnered on his way, the smell of burnt goat and the horrid carrot-orange smudges all down his shirt-front were still mildly offensive. Shrugging, John slipped into one of the disused chambers in the dungeons and yanked on the cloak he stored there before continuing down towards the Slytherins' lair. He paused at the doors, whispered, "Unicorn blood," and disappeared inside.

It was odd; if someone had entered Gryffindor tower in a cloak, there would be thirty-odd wands in the cloak-wearer's face within seconds. However, in the (surprisingly not empty) Slytherin common room, no one spared John a second glance. They were an odd bunch, John thought, but he supposed that lot felt much the same about the Gryffindors, as well.

Pausing at Sherlock's door, John first rescinded the enchantment Sherlock had placed (one of his own devising, though what exactly it did John wasn't sure) and then unlocked the door with his spare key. It clicked open and he nipped inside, pulling the door closed and relocking it before putting the enchantment back up and heaving a sigh. He tore off his cloak, threw it in Sherlock's chair, and slumped down on top of it.

Sherlock was on his bed, his legs crossed and every square inch around him littered with papers. He lowered the document he was reading and eyed John curiously before quirking a small smile at him. "Interesting day?"

John looked down at the mess on his shirt and wrinkled his nose at the memory. "I had a row," he sighed, looking back up and meeting Sherlock's eyes, "with my practice Potions' cauldron."

"You had a row with a cauldron?" Sherlock's eyebrow lifted delicately.

"In a manner of speaking."

Smiling, Sherlock disappeared behind his papers again, his voice quiet but edged with humour as he said, "I suspect the cauldron won that round."

There was no use shooting a dark look at him, hidden as he was behind that damned parchment, but John did it anyway. Then he settled back against the chair, exhausted, before letting out a small groan. How had he forgotten! He had a very long and very research heavy scroll due in the next day for Arithmancy, and he'd gotten so far as writing his name at the top of the parchment before falling asleep the night before. It looked like John was going to have another sleepless night, and another exhausting, miserable day.

Unless…

No. No way. Asking Sherlock to write his paper (even though he knew it would take the younger boy all of a half hour, whereas it would take John all night) was completely out of the question. It went against his moral code entirely.

But it was Sherlock's fault that he hadn't written it, in a way. And if John didn't keep his grades up he'd be forced to do extra work around the castle; those were the stipulations of his scholarship.

But: cheating!

But: oh God, sleep…

John licked his lips. "Sherlock. If you could possibly write this…Sherlock? Are you listening to me?"

Sherlock definitely wasn't. He had set aside the last parchment and was now perusing a different one, his eyes slanted in a way that suggested he was highly interested in what he was reading. Then he looked up at John and said, as if it were the natural conclusion to John's question, "I need to go to Gringott's."

"What, now?" John blinked at him.

"No, of course not. We'll go tonight."

"We…Sherlock. I have to write this essay, and if at all possible I really, really need to get some sleep." John ran his hand down his face and sighed. "Not to mention the problem of Gringott's being in London and us being in Scotland."

Sherlock tsked and waved his hands dismissively. "I've written your essay already; sleep is boring; and you're seventeen and thus perfectly capable of Apparating us both without arousing suspicion. I see no problems."

"You…wrote…" John coughed. "How did you…I mean-"

"Oh, do stop spluttering on," Sherlock yawned, but his tone was kindly. "I wrote your essay last night. Sleep, boring. Remember? Don't waste your time feeling guilty about it, either. It took me ten minutes to do and your mental faculties, limited though they may be, will be best used elsewhere. Now, switch me positions."

John gaped at him for a moment, and Sherlock gave a long-suffering sigh before standing and gathering all the papers from the bed, dropping the mess on to the desk. "Bed, now. We're going to Gringott's at midnight so whatever precious sleep you were hoping for, you'll have to get it now."

"I- thank you." John was still feeling a bit speechless as he crawled into Sherlock's bed, yanking the covers over him.

"You smell awful," Sherlock muttered musingly. "I do hope the house-elves remember to change my sheets later."

"Piss off," John said smilingly, wriggling further down into the mattress. It was rather cozy, Sherlock's bed, if small. John kept his feelings to himself, as rule, but it was hard to ignore the facts when he was surrounded by sheets that smelled like Sherlock and listening to Sherlock's murmured voice whisper, "Go to sleep, John. I'll wake you later." Yes- John acknowledged, letting his eyes sink closed and drawing the blankets tighter around him- he was still completely mad about Sherlock, painfully so, and Sherlock was still pleasantly ignoring the obvious for the sake of their friendship. Christ, but John was in a bad way, and what could he do about it? He followed this line of thinking down into a deep and dreamless sleep.