Some weird things--worse than the usual weirdness--have been going on at Mythos Academy, a school of myths and magic. After mean girl Jasmine Ashton is murdered in the Library of Antiquities, Gwen Frost is determined to figure out what's going on, especially since she was the one the killer wanted.

When one of their tightly-knit group mysteriously disappears, four high school girls find their friendship difficult to maintain when they begin receiving taunting messages from someone who seems to know everything about their past and present secrets.