They found Pomfrey's petrified body the next morning.

Dazai got away with it, of course. He'd left no evidence behind 'slaved over a puddle of blood for a whole hour, smelling like bleach 'and had scampered out of the infirmary well before dawn. By breakfast, when her body was discovered, Dazai had carefully feigned surprise. He hadn't eaten breakfast, and had acted too sick to try. Which isn't to say that Dazai escaped suspicion. No, that ship had sailed several months ago when the Daily Prophet decided to start calling him a demon. But there was nothing specific pointing his way, in the end. Dazai smilingly avoided punishment. Which made for something of a perfect conclusion, really.

Still. It was only a matter of minutes before the remaining students of Hogwarts started sending him glances and glares. And only an hour after that, Tracey was the first of many to outright suggest she wished Dazai was dead.