Erin Blake has one of those names. A name that, like Natalee Holloway or Elizabeth Smart, is inextricably linked to a grisly crime. As a toddler, Erin survived for three days alongside the corpse of her murdered mother, and the case—which remains unsolved—fascinated a nation. Her father's identity unknown, Erin was taken in by her mother's best friend and has become a relatively normal teen in spite of the looming questions about her past. Fourteen years later, Erin is once again at the center of a brutal homicide when she finds the body of her biology teacher. When questioned by the police, Erin tells almost the whole truth, but never voices her suspicions that her mother's killer has struck again in order to protect the casework she's secretly doing on her own. Inspired by her uncle, an FBI agent, Erin has ramped up her forensic hobby into a full-blown cold-case investigation. This new murder makes her certain she's close to the truth, but when all the evidence starts to point the authorities straight to Erin, she turns to her longtime crush (and fellow suspect) Journey Michaels to help her crack the case before it's too late.

Barely three weeks after catching the killer of Erin's mother and their biology teacher, Erin and her crew are back, up to their elbows in forensics projects. But this time it's with the full approval of their parents. With Uncle Victor at the helm, Erin and her best friends, Spam and Lysa, are prepping a new classroom for CSI summer camp, where they will serve as camp counselors. Meanwhile, Erin's super-hot new boyfriend, Journey, is graduating, just in time for him to take a position as Victor's intern in the new CSI lab on campus. Journey and Victor are going to take another look at the evidence in the murder trial that sent Journey's father to prison. The girls are under strict orders not to meddle with the murder case, but that's easier said than done...