Castle and Beckett Head to the Crime Scene on Castle Season 5, Episode 18: "The Wild Rover"
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 (guest star Cara Buono, Mad Men). 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.
Original Air Date: Castle Season 5, Episode 18: "The Wild Rover" airs Monday, March 25, 2013 at 10 p.m. ET on ABC.