That's when Harry pulls the Cloak off and uses the Cruciatus Curse on Amycus. When McGonagall says she won't go along with it, he spits in her face. Amycus says he'll blame the false alarm on kids who made Alecto press her mark so they'll face Voldemort's wrath. With Harry back under the Cloak, Amycus Carrow arrives, as does Professor McGonagall. Luna, still under Harry's Invisibility Cloak, stuns Alecto. It's there that Alecto Carrow spots Harry and touches her Dark Mark, letting Voldemort and the rest of the Death Eaters - including Snape - know she has Potter. Among the changes: In the book, Luna brings up the lost diadem of Ravenclaw and takes Harry to the common room to show him what it looks like on the statue of Rowena (Cho offered, but Ginny suggested Luna do it).
