When a man is found dead in an industrial cake mixer, Castle and Beckett trace the murder to an Irish gang in Staten Island and a beautiful bar owner named Siobhan O’Doul (Cara Buono). Much to everyone’s surprise, Detective Ryan has a complicated history with Siobhan and the Staten Island crime family from his days working undercover in narcotics. When the case hits a dead end, Ryan must go back undercover to expose the killer, complicating his relationship with his wife.
Elenco: Nathan Fillion , Stana Katic , Susan Sullivan , Seamus Dever , Jon Huertas , Molly C. Quinn , Tamala Jones , Toks Olagundoye , Seamus Dever , Susan Sullivan , Tamala Jones .