Complex sentence: After Harry saves Cedric when the maze attacks him, the two claim a draw and grab the cup together, which turns out to be a Portkey and transports the two to a graveyard, where Pettigrew and Voldemort are waiting.
Split into simpler sentences: After Harry saves Cedric when the maze attacks him, the two claim a draw and grab the cup together. The cup turns out to be a Portkey which transports the two to a graveyard where Pettigrew and Voldemort are waiting.