John figured the only way he was going to get this done without a) being obvious or b) getting himself expelled was to look for minor negative reactions rather than major ones. He'd been picturing himself calling Longbottom ugly or throwing a gardening instrument at his head, but nothing like that was necessary. A person could stub their toe and have a negative reaction to it.

The reaction John was going to work towards this class was annoyance. Teenagers could annoy adults without even meaning to. If John was doing it on purpose, it was sure to work.

He started by intentionally being late to class—he didn't have to try too hard, since he and Sherlock had spent too much time talking to Dumbledore. He would've had to run to make it… so he just strolled along, taking as long as he could manage looking at the vegetable patches.

Then he showed up… and Longbottom wasn't even there.

"Good day for you to be late," Mike told him as he walked in. "Longbottom realised he'd kept the kettle on. Ran out the moment he got here."

Jesus. What a clod.

"Where was he even making tea?" John asked, trying to hide his exasperation.

"You don't think the Teacher's Lounge is just a bunch of desks, do you? It's probably nicer than the common room."

Huh. John never honestly thought about it. Maybe he and Sherlock would have to break in sometime.

God, what had happened to him? He heard about something interesting and his first thought was of breaking and entering. Sherlock would be thrilled.

Longbottom came in, out of breath but still all grins. "Sorry about that. Thanks for not buggering off. Turns out Professor Moriarty turned it off for me. What a nice bloke."

John snorted and rolled his eyes, which got him a couple startled glances. He coughed and cleared his throat to try to play it off.

Well, being late didn't work. He'd just have to endanger one of his classmates with a carnivorous plant.

Poor Mike was sitting right next to him. John ought to have sat somewhere else.

But it turned out Stamford was safe, because today was one of the very few days where the plant they were working with was completely non-violent. They were being taught to juice hellebore, which was used in the Draught of Peace. While the plant was indeed poisonous, it had no reason to go attacking anyone, as it wasn't sentient. So John really couldn't hurt someone with it without it being obvious he did it on purpose.

John's mind was working like mad trying to think of how to upset Longbottom as the task was explained to them. It was easy—even the least competent student could figure it out. In fact, John figured out a shortcut halfway through the explanation—he showed them how to squash the plant with the flat of their knife and John could immediately tell that you would yield more juice by cutting slits in the sides before doing the squashing. Longbottom probably just didn't want students doing it wrong and slicing themselves.

Well, John was one of the best Herbology students in the school. If he was rubbish all class long, would Longbottom get frustrated?

Because the task was so easy, he had to get creative at being bad at it. He dropped his knife more than once, and let the plant slip onto the floor too, and when he got bored of dropping things, just plain rested his head on his hand. But Longbottom didn't pay him any mind—usually he didn't need to monitor John at all in this class, obviously, and was busy hovering over the students that frequently had trouble—and thus couldn't reprimand him for not paying attention for a long while.

Finally, Longbottom came over.

"John, you haven't done anything," he said in surprise.

"I just don't understand how to do this, professor," said John sombrely, maybe hamming it up more than he needed to. "No juice is coming out."

He leaned in, like he was going to tell a secret. "I didn't tell the class, because I don't trust everyone to do it right, but if you make a couple slices in the sides, you can juice it a lot easier."

John made the most helpless face he could muster. "I tried that."

"Here, I'll show you," he said, the perfect picture of patience. John had to bite his cheek to keep from sighing. "Oh, here's the problem," Longbottom said. "Dunno how you'd cut a thing with a knife this dull. Here, I'll sharpen it." Longbottom did a spell on the knife. "You should be good to go now. And if not, we'll be doing this again on Wednesday. I'm sure you'll have it by then."

How was anyone this pleasant? Maybe he was cursed after all,

John played with the plant mournfully for the next hour, prodding it with his now sharp knife—it pathetically dribbled a few drops, but nowhere near as much as they were supposed to be getting. How embarrassing it would be to have to tell Sherlock that he failed.

But that thought alone made him more determined than ever.

With that embarrassment in mind, an idea came to him. A perfect, genius idea. Good timing too, because class was nearly over and he was not going to tell Sherlock he couldn't do something as easy as upsetting one measly professor.

So he put his finger down on the cutting board and came down on it with his knife.

He accidentally cried out, not having meant to. It hurt a lot more than he expected it to and was bleeding kind of profusely. Jeez, it was just a little cut. The blood just seemed melodramatic.

The Hufflepuff to his left seemed to agree, because he glanced over, saw the gore, and fainted. That was when Longbottom noticed.

"John!" he yelled. "God, where's your head at today?" he exclaimed. Good thing John's finger hurt something awful, else he might've pranced 'round the room with glee. That was a negative reaction if he'd ever seen one, and all he'd had to do was give himself a little cut to cause it. Easy.

"Fucking shit, John," Mike yelled (not seeming to mind using profanities in front of his professor), "You've cut your finger clean off!"

John blinked in confusion. No way. He hadn't come down on it that hard.

But he looked down at it, tilting his head. Alas, a good half of his finger was gone.

Well, Longbottom's knife sharpening spell worked a lot better than John expected.

John was probably in shock—or possibly so glad Longbottom wasn't under the curse that he was mad with pleasure—because his only response was, "Oh. So I have."

Longbottom looked angrier than John had ever seen him as he wrapped a piece of cloth 'round John's stub. "Grab the finger," he said tersely. "To Madam Pomfrey's with you. The rest of you, dismissed."

Class was almost over anyway, so everyone had been packed up. The boy who'd fainted woke up a couple seconds later, but was having trouble staying conscious long enough to stand with the amount of blood in the greenhouse, so Longbottom picked him right up—was a lot stronger than John expected, actually—and they made their way to Pomfrey.

"You alright John?" Mike asked. "Want me to come?"

"I'm fine," John said with a genuine grin. Longbottom wasn't cursed. Everything was wonderful, clearly. Mike's expression was more than a bit startled by John's palpable delight. "See you at training later."

John followed Longbottom through the grounds, the tip of his finger in his right hand and his left aloft so it bled less.

Once they were away from everyone else, only the unconscious kid around to overhear, Longbottom hissed, "John, what the hell is going on?"

"What? My hand slipped."

"No it didn't. You were doing that on purpose. All of it. You could juice hellebore in your sleep. I wouldn't've sharpened most students' knives for them, but I was confident you were completely competent with it."

"Are you proposing I cut my finger off on purpose?" asked John, trying to sound offended.

Longbottom sighed, looking at John with narrowed eyes. "I've known Gryffindors to do many stupid things, if only for a good cause."

John gave a patronising look. "What good cause would I have to cut my finger off, professor?"

"I don't know," replied Longbottom, sounding tired, "but the whole school's been off lately. I don't know what to think anymore."

So Longbottom had noticed the other professors acting strange too.

John was tempted to tell him something right there, but knew he couldn't make a move that big without asking Sherlock. So he walked the rest of the way in silence.

John was nervous to go up to the hospital wing at first, since Pomfrey was under the Curse. But she was, if anything, more pleasant than usual because of it—as Sherlock had mentioned earlier that day—so it was all a breeze. His finger was back on within two minutes of entering—honestly it was so easy John could've probably done it himself—and Pomfrey was onto the groggy Hufflepuff with some potion.

"John…" Longbottom said significantly, glancing at Pomfrey to make sure she was too far to hear them, "Whatever you're playing at, be careful. And if it's ever too much, come to me. I know better than anyone how much students love to save the day, but we professors aren't useless. We're here for you on every front."

John smiled. "Yeah. I'll remember that. And I promise I won't cut my finger off again," he added.

Longbottom glared. "Yeah, I bloody well hope not." Then he made his way from the wing, shaking his head and muttering about Gryffindors.

John followed him out and nearly ran into Sherlock, who'd been sprinting at him. Clearly he'd already heard what happened, or he'd not be on this side of the castle—he'd also not be running around like a madman, most likely. Mike Stamford probably told him, bloody snitch.

"Hey," John said casually, waving with his newly put together hand.

"You cut off your finger?" he asked incredulously.

"Right to the point then. No hello kiss for your favourite boyfriend?" Sherlock looked at him dubiously. "I didn't mean to cut it off," he muttered. "It was supposed to just be a cut, but Longbottom sharpened my knife to supernatural levels, so it kinda, you know. Came off. But it's good as new now, see?"

"John…" Sherlock said, something between amazement and exasperation in his voice. "You're a complete idiot."

John huffed out a quick laugh. "After what just happened, I can't really argue with you." They started to walk and John added quietly, "But the good news is that Longbottom is curse-free."

"The bad news," Sherlock replied, "is that Hagrid is not. I was incorrect in my assumption that giant resilience would protect him—the Unforgivable Curses are clearly too strong."

John's stomach knotted up. "You're sure? It took a lot for me to upset Longbottom."

"Hagrid normally cries over everything. I blatantly brought up his long dead pet Aragog and he was completely unbothered. I also caused him to stub his toe and he didn't curse once. He's definitely Imperiused."

Toe stubbing. John knew that was a good test of irritability.

"So just Longbottom then," John said. "What good does that do us though?"

"It gives us allies to rely on if the worst should happen."

"And what's the worst that could happen?" asked John apprehensively.

Sherlock's response wasn't comforting, because it was a complete change in subject. He stopped walking. "I have something for you."

But John was so pleased to be told he was getting a gift that he let himself be distracted. He was grinning when he asked, "Really? What?" Sherlock pulled the gift from his robe, at which John stared at in confusion. "It's a wand."

"No, it's a Zonko's wand. It's fake."

"Okay…"

"I'd like you to carry it around," Sherlock specified. "You must have it at all times, like the pin."

"Why?"

"Please, John, will you just do this for me?"

John met Sherlock's somewhat manic eyes with suspicion. "Is this to do with Moriarty?"

"No so loud," Sherlock hissed. "Just… please. Please carry it. When the time comes, you'll know what to do with it."

John looked at him probingly for a moment, but then took the wand from his hand. "Alright, alright, I'll do it."

"Thank you," Sherlock said in relief. "Oh, but be careful," he added, "If you actually try to do a spell with it, it'll give you a black eye."

"Great," John muttered, putting it inside his robes. "Can we get some lunch now?"

Sherlock groaned. "If you insist."