A brunette head lifted upwards at the sound of Harry falling to his knees a few feet away. "Ello Harry. Took you long enough." Cedric Diggory said as he closed his book. (Takes place after the final task.)

Harry's name coming out of the goblet of fire was the last straw. (Or Harry snaps and does the sensible (or idiotic depending on who you ask) thing. He leaves.)