This is a challenge to a Harry Potter story. There is going to be slash between Harry and Barty Crouch Jr.
When Harry's name came out of the Goblet of Fire not only Ron but also Hermione turn their back on Harry (and more or less the whole school...)
Harry decides, he doesn't need friends like that and closes himself of from his peers.
While throwing himself into his study's to not get killed in the tasks he realises something wired in his DADA teachers demeanour.
Nothing obvious but some subtle gestures, (a glint in his eyes while casting an unforgivable, an hateful look at Dumbledore here a disgusted look at Malfoy there...) made Harry suspicious.
Not to forget the wonderful aura surrounding the man (a strong dark magical core).
He decides to investigate and finds something he very much beguines to like...
What you make of the story from here is up to you.
I hope someone takes it up.
Ps: Sorry for any spelling and grammar mistakes I made.