Former best friends Hanna, Aria, Spencer, and Emily, who lost their best friend and leader, Alison, years ago when she disappeared, find themselves in grave danger when they pursue the truth about Alison.

When Will Halpin transfers from his all-deaf school into a mainstream Pennsylvania high school, he faces discrimination and bullying, but still manages to solve a mystery surrounding the death of a popular football player in his class.

Shy and unremarkable, seventeen-year-old Matt Lathrop is surprised and flattered to find himself singled out for the sexual attentions of the alluring Skye Colby, until he discovers the evil purpose behind her actions.