Wise beyond her 13 years, Frances McCausland has always approached life with logic and reason. In her effort to be "grown up," she rejects all childhood tendencies in herself and those around her. That is, however, until someone starts playing destructive pranks in her small community, and all evidence points to Frances as the culprit. Upon further investigation, Frances discovers she is actually being framed by a mischievous Boogeyman who resides under her bed. Desperate to solve the mystery, Frances reluctantly enlists the help of Larry Houdini, her little brother's imaginary friend. Contrary to Frances' rational nature, Larry must teach her to rely on her imagination in order to defeat the Boogeyman, clear her name and save the town.