What events occur when Camelia goes home?

Camelia goes home to find her parents are not there yet, and that everything is dark. She goes inside and turns on the lights, and someone begins calling her. No one answers. Camelia orders a pizza, and then Ben calls to see if she is okay. Ben says he is going to come over. The phone rings again, and the voice on the other end tells Camelia not to forget the mailbox.