Harry Potter disappears off the street. His friends and family are baffled with no sign of a struggle, and no ransom. The same day a boy falls from the sky in New York city at the feet of Tony Stark and Bruce Banner. He has no memory of who he is, or where he came from. While the Weasley's try their hardest to get Harry back the Avengers try and cope with an amnesiac boy-who-lived
The remaining three Champions decide to honour Cedrics memory, see how the continued contact changes things for Harry.
Hermione needs a break from Ron for the night and sneeks out to see Harry, Ron goes to see the rest of the gang but nobody really wants to see him at 2 o'clock in the morning . . . go figure.
What might have happened if Voldemort had been inclined to play with his prey before the kill. Rated for toture and language. Might be added to if the mood strikes me. Cheers.