When a two-year-old girl is discovered missing from her home, Beckett is called in to assist with the investigation only to discover that the FBI agent in charge is, in fact, her ex-boyfriend. The two of them try to put aside their unresolved feelings as they race to find the girl, but when Castle inserts himself into the investigation, competition quickly heats up for Beckett’s attention.

Castle and Beckett investigate the murder of a missing plastic surgeon who is found dead in the front seat of his car after a week of being parked curbside. As they delve into the twisted world of surgery obsessed patients and secret operations, Castle experiences a fatherly rite of passage as Alexis attends her first prom. And while looking into Beckett’s past, he unearths information that could end his relationship with her forever.