Hanna Marin is smart and outgoing. Meanwhile, the school loner, Caleb Rivers is shy and mysterious. Hanna attempts to befriend Caleb but her actions cause war when Mona Vanderwaal, Hanna's best friend reveals her crush on Caleb. Hanna promises to help Mona out with her crush, but instead she ends up falling for Caleb. One to many promises seem to be made, as Caleb and Hanna begin to date, Mona promises to support them, until she rudely tortures them with their secrets. Mona even threats to kill Hanna, but Caleb is to attached to Hanna to let her go, but sometimes you have to do what's right.