"Well," Harry began as he led his friend forward. "I need to prove someone wrong."
"Who?"
"Hermione."
"Of course. And what's she wrong about now?"
"She thinks the troll just wandered in on its own during the Halloween Feast."
"Didn't it?"
Harry nearly pulled his hair out. "No, of course not! Honestly, what's it like to see the world in little papery two-dimensional crayon drawings? Why am I friends with you two again?"
Oh dear, he was channeling Tom again.
"Because no one else will be friends with you, Harry." It was a joke, but only halfway. Harry had confided in Theo regarding his anxiety over his friend-making skills, and Theo had taken it upon himself to mock these anxieties until they didn't make Harry anxious anymore. So far, it was working decently. Harry was a lot less nervous these days.
"True, but not the point."
"Then what is the point?"
"The point is that someone let the troll in as a distraction."
"A distraction for what?"
"I don't know yet."
"...right. And how do you know all this?"
Well, to be fair, he didn't. He was just postulating – but Tom agreed, so he was sure he was right. "I just do."
"...ok. And why am I here?"
"Well, these things are always safer with two people instead of one. Plus, I need someone to verify my findings in case Hermione doesn't believe me."
"And why would she believe me?"
"She may not, but I believe that if she interrogates us separately, she'll be able to deduce the truth of our story; she's very intelligent like that."
"And why would I let that Mudblood 'interrogate' me?"
"(A), don't call her a Mudblood, and (B), because you want to stay on my good side, of course."
"...yes, I do."
Harry smiled.
"So...where exactly are we going?"
"Well, I don't know exactly where we're going, but we're going to check out the third floor corridor."
Theo's eyes bugged out. "We're going where?"
"The third floor corridor."
"And why, in the name of Merlin, Morgana, and all things holy, are we going there?"
"Well, you see, I believe that there's something hidden in the third floor corridor, something that's not usually there, or else Professor Dumbledore wouldn't have announced it at the feast. My theory is that whoever let the troll in did so in an attempt to create a distraction while they came up here looking for whatever it is Professor Dumbledore hid here."
"And you, in all your infinite wisdom, decided to come looking for it."
"Quite."
"If I die a painful death, I'm coming back to haunt you."
"That seems fair."
Theo sighed. "Maybe Dumbledore was exaggerating...maybe he just didn't want people looking around up here."
"I don't think so, but if you'd prefer it, we can pretend that that's true for the time being."
Theo shot him a deadpan look. "No, you've already ruined it."
"Just being honest."
"Not one of your better traits, Harry."
"So I've been told."
Indeed, Tom had told him this many times. Speaking of Tom, he was fully in support of Harry's little expedition. Tom (quite reasonably) believed that there was something going on at Hogwarts, some sort of plot, the details of which neither he nor Harry were privy to. And he didn't like that. With Harry's frequent headaches in Defence Against the Dark Arts, Tom had his suspicions that his master's soul might have something to do with it, which meant that their ignorance of the situation was a disadvantage they could not afford.
So, Tom had insisted that they must find out what was hidden on the third floor corridor. Moreover, Tom had further insisted that Theo be brought along – apparently, these sorts of things were always safer in pairs (not to mention, if they were caught, it would be easier to explain away the expedition with someone else to vouch for his innocent intentions), and since Theo was already honor-bound to keep his mouth shut, he was the perfect choice for a partner in crime.
Harry grinned as they reached the corridor. "Here we are. Now let me know if you find it."
"Find what?"
"Something suspicious, I suppose."
Theo groaned but started trying doors nonetheless. "Alohomora...alohomora...alohomora..."
It turned out that a significant majority of the rooms branching out of the third-floor corridor were dusty, unused classrooms that had been cleared out, making their task quite straightforward... and tedious. Whether time was slipping away rapidly or dragging its feet, Harry had no clue. The whole affair was monotonous either way.
They were roughly halfway down the corridor when a shuffling sound echoed from the stairs.
"Harry! Someone's there!" Theo hissed, sounding rather alarmed.
"I know, it's Filch – cast the disillusionment charm and go sit in the corner for a couple of minutes."
"Harry! I can't cast the disillusionment charm!"
Harry frowned at him. "But I showed you just the other day!"
"Well, some people can't replicate fourth-year spells after being shown only once."
"Oh."
"Oh indeed."
Harry sighed. "Fine – alohomora – let's hide in here," he said, pulling Theo into the room he'd just opened, feeling the boy stiffen as he did. "...what?"
A very pale-looking Theo shakily pointed behind him, causing him to spin around.
"Oh...that looks like a three-headed dog."
"Harry, I think that is a three-headed dog," Theo whispered hoarsely.
"Yeah, I think you're right."
At that moment, a deep growl resonated through the room, and both boys jumped at the sound as the creature opened its gigantic eyes.
"Good doggy," Harry said, smiling hopefully.
Apparently, it did not appreciate being called a 'good doggy,' because it immediately let out a howl, prompting the boys to scramble out of the room, nearly falling over as they slammed the door behind them, wasting no time before they ducked into the next room Harry quickly unlocked.
Once they were safe, Theo looked over at Harry, who was grinning widely.
"Well, that was...rather cute, wasn't it?"
"You're so weird."
"And you're blind. It was adorable. Did you see its eyes? They were so big and black!"
"They were kind of hard to miss."
Harry sighed. "I suppose we'll just have to agree to disagree. At least we got what we came for."
"You think someone let a troll in so they could come up here and check out the three-headed dog?" Theo asked incredulously.
Harry laughed. "No, of course not! They were looking for whatever's beneath the trap door the dog was standing on."
"...oh."