When an ER physician is gunned down in the street, Castle and Beckett soon discover that the victim was a mob doctor to a Mafia family run by an old friend of Castle's. Also, against the backdrop of Christmas, Esposito and Lanie reach a defining moment in their relationship.

When a young Latin telenovela actress is murdered, Beckett and the team delve into a case that is as flamboyant and full of intrigue as any telenovela. Meanwhile, Castle is hired as private investigator by the show's sultry star to pursue the case from another angle.