It figured that Professor Reilly was evil. They hadn't had a really evil Defense professor for a while, so they were due. After all his talk of teamwork and slayers and things that go 'bump', the strange teacher was probably plotting to kill them all in their sleep, or something equally nasty.
As Hermione pointed out, he didn't seem evil, and they'd been wrong before- as evidenced by Professor Quirrel in their first year. Plus, Harry's scar didn't hurt around Professor Reilly, and the man had proven to be harsh but fair. He certainly didn't fit the profile of 'Death Eater', but, as always, Harry and Ron were quick to judge.
Currently, the two boys were plotting ways to reveal Professor Reilly's guilt, each one more complicated and ridiculous than the last.
"We could put Veritaserum in his flask!" Ron suggested. "Yeah…" replied Harry, mulling it over. "That could work-"
"Except Snape keeps his supply heavily charmed against theft, and we can't brew it ourselves, as it requires Class 1 controlled magical substances." Hermione snapped, not looking up from her Arithmancy text. "And how would you go about getting into his flask to begin with?"
"We could beat it out of him!" Harry said, with a decisive nod.
"And if he's really a Death Eater, he's going to be absolutely terrified of three school children." She said dryly. "Oh, and Harry, I think you've been spending a bit too much time with Goyle. You're displaying a disturbing propensity for Muggle violence."
"We could use Avada Kedavra!" Ron said excitedly.
By this point, Hermione felt like yanking out her own hair in frustration, and was seriously questioning why she was friends with these two.
"IT DOES DEATH." She shrieked. "Why don't you just bloody ask the man if he's an agent of the Dark Lord, and if he hexes you, it means 'yes'."
"If who is 'an agent of the Dark Lord', Granger?" an unexpected voice said from behind them- Dear Merlin, they had to stop discussing their plans in the library, it was entirely too easy for people to overhear them- and there was Professor Reilly, holding a book on Pensieves, and looking much too interested in their conversation.