Vanishing Girls marks readers' introduction to author Lisa Regan's wildly popular character Detective Josie Quinn. Quinn, who is suspended from the police force at the start of this novel, is a dedicated, intelligent, and relentless detective who does the best that she can.
The novel begins against the backdrop of the search for a missing girl called Isabelle Coleman in small-town Denton. Police and townspeople search feverishly for Isabelle, hoping to find her before it is too late. The police and town authorities only have two leads: her cellphone and another girl - who was found alive but barely functioning - who authorities did not know was missing.
This girl, who doesn't speak other than to say her name: Ramona, gives Josie the idea that Ramona and Isabelle's cases may be connected. As she races to find Isabelle alive, Detective Quinn also continues to look for evidence that 1) the cases are connected and 2) that, as per her hypothesis, more girls are in danger.
Detective Quinn's hypothesis is proved to be true. She finds another woman who escaped her captor and whose case was incorrectly determined to be a hoax by the police department. With information from this victim, Josie finds Isabelle and the other girls.
