Question: Why doesn't Adam kill Kate? Is it because at the start of the movie she said that she would dance with him later or simply because she is his girlfriend?

Chosen answer: He doesn't kill her because she was the only nice one, whereas her friends( Paige, Lily, etc.) were all mean to him at the beginning.


Question: If the killer was Adam wanting revenge for the dance, why did he kill Campbell and the other woman we see him drag through the door, who I assume is Dorothy's step mum? But if Dorothy is the killer, why kill her boyfriend?

Chosen answer: Adam killed Campbell to make sure he wouldn't interfere with his plans. The presence of Campbell's head at the house probably means that he had come by to guard or to snoop. As for Dorothy's stepmother, Adam most likely killed her to both empty the house and to further frame Dorothy as the killer - after all, Adam has no (apparent) reason to kill her, but Dorothy does.

Question: I don't get the ending. We see Adam shot the masked person who is Dorothy, so I figured the killer was Dorothy, but reading a correction entry it states that it's obvious the killer was Adam. If the killer was Adam then how did he get Dorothy in the suit and mask and then make her attack her friend before shooting her?

Chosen answer: If you remember, Dorothy kind of stumbled into her friend from around a corner before they both fell down the stairs. Adam could have quite easily forced her into the costume and then pushed her, making her seem like she was trying to attack her friend.