Two more weeks, and Lily Hopper is officially finished with boarding school! When she receives a mysterious note inviting her to join the anonymous senior class Jester in executing the end-of-year prank, Lily sees her chance for a little fun. The Jester turns out to be Taggart Swell, her ex-boyfriend. She'd back out, but he has a brilliant plan to steal the school's yearbooks, targeting Lilly's prom date: Senior Class President, Daniel. As the pranksters hide clues across campus for Daniel to find, Lily and Tag find themselves dodging Campus Safety guards, night owl teachers, a troop of freshmen, and even Daniel himself.