When a group of eighth-graders find the decomposed body of woman wearing a medieval princess dress, the team is on the scene to investigate. With Booth incapacitated due to a back injury, Agent Payton Perotta steps in to help with the investigation. With insight from "squint" Colin Fisher, a self-professed geek and expert in the language of sci-fi, the team identifies the woman as a promotional model from ImagiCon, a convention for fans of comic books, video games and other sci-fi genre entertainment. Brennan and the team must navigate through the outlandish landscape of ImagiCon in order to track down the killer. They soon find the victim may have owned a highly valuable piece of sci-fi memorabilia that many would kill to possess.