Note: For an apology the months-long hiatus, please see my Tumblr. (The link is on my profile page.)

As usual, Sherlock took charge of the situation before anyone could object.

"John, come with me," he said, and began marching off.

John looked at the adults.

"Go ahead," Harry sighed. "Whatever Sherlock has planned, I don't have the energy to try and stop him right now."

"Maybe you can keep him from doing anything too outrageously dangerous," Longbottom added.

John thought the professor was probably overestimating his influence. Nevertheless, he followed Sherlock down the corridor.

He was still trying to wrap his head around this latest turn of events. How could Moriarty have been attacked? Did this mean he had an accomplice, who had turned on him? Or had he poisoned himself to throw the Aurors off his scent?

John was leaning towards the latter. It seemed like the sort of clever, mad thing Moriarty would do. But Ron and Harry weren't stupid, and they already had plenty of reason to suspect Moriarty. Surely, this would only delay his arrest for a little while. Unless…unless he had another trick up his sleeve…

"Have you got any parchment?" Sherlock asked abruptly.

John came out of his reverie with a start.

"What?"

"Parchment," Sherlock repeated. "Or maybe a journal? A book you don't like too much? Anything you can write on?"

"Er, not on me."

Sherlock cursed under his breath. Before John could ask why he needed something to write on, the other boy took off again. Grumbling, John followed him all the way to Ravenclaw Tower.

He waited in the common room while Sherlock went upstairs, presumably to disturb all of his classmates by rummaging through his trunk in the middle of the night. Eventually, he returned with a pocket-sized notebook.

"Annecto verbius," said Sherlock, tapping the book with his wand. It glowed blue for a moment, and then…nothing. However, Sherlock seemed satisfied.

"Keep it nearby at all times," he said, handing the book to John. "Against your body, if possible. It will get warm when I send you a message."

John tucked the notepad into the waistband of his trousers. Though not exactly comfortable, it was discreet: his robes hid the bulge completely.

"And I need this, because…?"

"You're going to have to be my eyes and ears once I'm locked up. This way, I can tell you what to look for, and you can report back."

John looked up, startled.

"What do you mean, once you're locked up?"

"Obviously, when Moriarty accuses me of poisoning him, the adults will have to act."

John groaned. Of course. That was Moriarty's final trick: to frame Sherlock for his crimes. It was so simple, he felt like an idiot for not working it out on his own.

"But you have an alibi," he said. "You were with Ron and Professor Longbottom, weren't you?"

Sherlock shook his head. "Not with them so much as near them. We were all shadowing you from different positions. Theoretically, I could have slipped down to the dungeons to poison Moriarty and slipped back before anyone noticed I was gone."

"Ron and Harry won't believe that."

"Maybe not, but they can't appear biased. They'll have to take me into custody, at least until my name is cleared."

Sherlock looked John in the eye, but not in his usual, unnerving, Sherlock-y way. For once, he wasn't looking only to deduce.

"John," he said, "it's up to you now."

O0O0O

When Sherlock didn't appear at breakfast the next morning, John told himself not to panic. Sherlock had anticipated this. Everything was under control. In fact, his absence didn't even mean that he'd been arrested, necessarily. He might have simply decided to skip breakfast in favor of working on the case—he never seemed to eat, anyway.

Then Sally Donovan came by to dash this hope to pieces.

"I just saw Harry Potter and Ron Weasley leading Holmes into the headmistress's office," she informed him.

John had been raised to believe one should never hit a girl, but the smug look on Donovan's face was seriously tempting him.

"Sherlock was framed," he said.

Donovan's expression became pitying, which was somehow even worse.

"I warned you, didn't I?" she said. "I told you to stay away from that freak."

"Yeah," said John. "And thank God I didn't listen." Then he walked away before she could respond.

His first impulse was to burst into McGonagall's office and defend his friend's honor, but he nixed that plan after picturing the look on McGonagall's face. With nowhere else to turn, he walked down to the greenhouses, where he found Professor Longbottom watering the Mandrakes.

"Sally Donovan told me she saw Ron, Harry, and Sherlock going into the headmistress's office," he said without preamble.

Longbottom set his watering can down with a sigh. "Yes, I expect she did."

Usually, the professor had an almost Buddha-like calm about him when he was at work, but today he looked haggard and worried. John regretted bothering him, but not enough to leave without getting any information Longbottom could provide.

"So Sherlock was right," said John. "Moriarty is trying to pin it all on him."

"He's saying that Sherlock attacked him last night," Longbottom confirmed.

"But it's his word against Sherlock's. That's not enough to convict him, is it?"

"It wouldn't be on its own. But three different paintings told Harry and Ron that they saw Sherlock going down to the dungeons right before Moriarty was found."

John supposed this was the moment when most people would begin to have serious doubts about their friend. He brushed the thought away immediately.

"It's a trick," he said. "Moriarty tricked the paintings somehow, or—or made them lie for him."

"That's what Sherlock thinks," said Longbottom. "He has several theories as to how it might have been done, but without any hard proof, I'm afraid that's not going to do him much good."

This is what Sherlock meant when he said it was all up to me now, John thought. I have to find the proof. But where do I even begin?

"You…you don't believe Moriarty, do you, professor?" he asked.

"No, I don't," Longbottom said without hesitation. "But others will. I'm guessing Miss Donovan didn't come to you because she was worried about Sherlock's wellbeing."

John recalled Donovan's smug face, and felt the urge to punch something all over again.

"That cow," he spat. He was too angry to care that he was talking to a teacher.

"John, please, try to look at it from her point of view," said Longbottom. "Sherlock is a pureblood, and a lot of his relatives were in Slytherin. Everyone knows he's a genius, and…well, even you have to admit, he's not always pleasant to be around. Moriarty, on the other hand, is a half-blood, and he's kept a low profile up till now. If you only knew both boys in passing, who would you think was telling the truth?"

John said nothing, but they both knew the answer.

Longbottom patted him on the shoulder. "Don't worry. Something similar to this happened to Harry in our second year, and it all got sorted out in the end."

John nodded, but all he could think about was Moriarty's words echoing in his head:

You had your chance, Sherlock. Now I'll have to destroy you.

O0O0O

He was on his way to Transfiguration when he felt it: a burst of warmth against his abdomen. He whipped the notebook out of his waistband so fast that he nearly gave himself an extremely awkward paper cut. Written on the front page, in Sherlock's trademark scrawl, was a single sentence:

Watch who talks to Moriarty.

O0O0O

Moriarty was released from the hospital wing the next morning. It soon became obvious that Sherlock's instructions would be easier said than done: Everyone wanted to talk to Moriarty about his supposed brush with death. A small crowd surrounded him all through breakfast, asking him questions, telling him how glad they were that he'd survived, and offering to get him more sausages. It made John's blood boil.

"You need to calm down, mate," Mike whispered. "You're not going to make him confess by glaring at him."

John said nothing. If he explained about Sherlock's message, Mike would want to help, and John was more determined than ever to not let anyone else get caught up in this mess.

"Blimey," said Henry. "He doesn't look happy, does he?"

John followed Henry's gaze. Sebastian Moran had just entered the Great Hall, looking even surlier than usual. John didn't think much of it, until he realized that Moran was heading straight for Moriarty.

Moran cut through the crowd like a shark through a school of fish. As people dived out of his way, Moriarty's dismayed face emerged for a moment before disappearing again behind Moran's bulk.

John stood up to get a better view. Moran was bent over, whispering something in Moriarty's ear. The other boy looked around before furiously shaking his head. Even from across the Great Hall, the message was clear: Not here.

John had never seen Moriarty look so cagey. What had Moran said to him?

The question ran on a loop in his head all afternoon. Then, halfway through History of Magic, it clicked.

"Sorry-professor-I-have-to-go-to-the-loo!"

Professor Binns, who was in the middle of a particularly mind-numbing lecture on the Broomstick Tax of 1784, didn't even look up as John bolted out of the room. But a few of his classmates were rather startled.

Minutes later, he burst into the classroom that Ron and Harry had transformed into a temporary office.

"Polyjuice Potion!" he gasped.

The Aurors looked at him with mingled surprise and bewilderment.

"Er, what?" Ron asked.

John took a few much-needed, deep breaths before launching into his explanation.

"The day before yesterday, Sebastian Moran cornered Sherlock in the loo and beat him up. What if he pulled out some of Sherlock's hair? Moriarty could have put him up to it—offered him money or the answers to his next Potions exam or something. Then Moriarty put the hair in a Polyjuice Potion. It was him the portraits saw going down to the dungeons, not Sherlock."

"Polyjuice Potion takes weeks to brew, John." Harry said this cautiously, as if trying to burst John's bubble as gently as possible.

"But you add the hair last, right?" said John. "Moriarty told Sherlock he'd been watching him almost since he got off the Hogwarts Express. He might have been planning this for just as long."

There was a slight pause.

"What do you think?" Ron asked Harry.

"It's more plausible than your evil twin theory," he said.

"Loads of people have twins!" Ron huffed. "And that was just a passing thought, anyway. Let it go."

"All right," said Harry. "I guess we should have a talk with this Moran."

"He's probably still in the Great Hall," said John. "If we hurry, we can catch him before—"

Harry cut him off. "By we, I meant Ron and me." He looked at John sympathetically. "I'm sorry. I know you want to help, but it's just too dangerous."

John protested, but it was no use. The adults were convinced that allowing him and Sherlock to help with the case had been a mistake, and one that they weren't going to make again. Thus, John found himself standing alone in the corridor, at a loss for what to do next.

The thought of going back to History of Magic was unbearable. The common room would be empty at this time of day, and he wasn't sure he wanted to be alone. Most other places would leave a slight possibility of running into Donovan again. In the end, there was only one option that didn't sound torturous.

He headed for the hospital wing.

O0O0O

Molly looked terribly small in the large hospital bed. A lump formed in John's throat as he watched her motionless form.

"We know who did this to you, Molly," he said softly. "And we're going to make him pay. I promise."

Behind him, the door to the hospital wing creaked open. John cringed, fully expecting to be accosted by an outraged Madam Pomfrey. Instead, he found himself face-to-face with none other than Irene Adler.

"What are you doing here?" he asked.

Irene flushed. "I just came to see how Molly is doing!" she said angrily. "I tutored her in Potions, and…and…"

Irene looked past John at Molly, and her words seemed to leave her.

There was a tense pause. Then, sighing, John offered Irene his chair.

"Thank you," she whispered.

John felt bad for snapping at the girl. He knew his anger was misdirected. Irene Adler was an opportunist, but she was no murderer. She wasn't the reason Molly was in a coma.

"She's such a sweet girl," said Irene. "Why would anyone do this?"

"For fun," John said bitterly. "For the power trip. For the thrill of getting away with it."

Irene turned to him, and there was a fierceness in her expression that he had never seen there before.

"You know who it is, don't you?" she said.

John nodded.

"Tell me."

A day ago, John would never have imagined himself confiding in Irene Adler. But now Sherlock was gone, and almost everyone believed he was a criminal, and if anyone would believe the truth, it was Irene. The words poured out of John like a waterfall.

Irene listened intently. When he finished, she sat in silence for a long time before saying anything.

"If Moran confessed to getting Sherlock's hair for Moriarty, would that be enough to sort everything out?" she asked.

"I don't know," said John. "But it would cast suspicion on Moriarty, at the very least, and that's better than nothing, right?"

"Quite right."

Irene stood up.

"Well then," she said. "What are we waiting for? Let's find Moran."