Following a clue from Marcy Towns as to the whereabouts of Quentin Quinn, Violet searches the Ghost Gap, a little-known cavern deep in the woods. Instead of finding the missing boy, Violet discovers the strange purple light hiding at the bottom. Sensing the light is weak, Violet offers the creature her father’s flashlight which it quickly consumes.

The next day, a fire engulfs the New Tomorrow particle accelerator construction site. Violet rides over and uncovers a message from the Order of the Arranger, presumably warning of the approaching end-times. Officer Ron and Chief Holt suspect the fire has been started using the town’s missing Fourth of July Fireworks, though no arrests are made.

At the Question Mart, Violet meets FBI Agent Adam Oberman, a young investigator who confesses his ambivalence about working for the FBI. Admitting he would rather have pursued a life in musical theater, Violet feels a connection and decides to tell him everything she’s learned about the town.

With help from Ms. Peterson, Violet records a Morse code message in the woods, which may have been sent from Quentin Quinn. Decoding the message, Violet learns it is a clue involving the missing library book, Moonlight Woods. At the library, she finds a digital copy, which leads her in search of a crystal cave somewhere in town. What danger will this latest clue lead her to?