Kinsey uses a key to seek vengeance on a school bully. A troubled Nina finds a sympathetic ear. A long-buried memory casts Rendell in a new light.

Kinsey explores the sea cave with the Savini Squad in tow, Nina confronts Ellie over Joe, and Tyler sabotages his relationship with Jackie.

As pieces begin to click into place for the Locke siblings, Ellie opens up about her connection to Dodge, and Kinsey comes clean with her friends.

Gideon forces Ellie to take him to the missing key, putting an old classmate's life on the line. Nina and Bode attempt to unlock the Harlequin Chest.