Previously on ABC Castle television series, Beckett and Castle investigated a brutal mystery of a lottery winner. He was murdered inside his room leaving his vault empty with the lottery ticket behind. The team lead to many suspects and lastly they unveil the truth about the ticket which was taken by the victim to his neighbor friend. His friend died and lastly the murderer was his non biological son who wanted to take what is right for him. Meanwhile, Martha inherited a million dollars from her former fiancee Chet and used it to honor his memory.

This Monday, hit American comedy-drama Castle TV show airs its newest episode 15 entitled "The Final Nail". The episode is directed by John Terlesky and screenplay written by Moira Kirland. What kind of criminal mystery revolves Castle Season 3 Episode 15?

Castle Season 3 Episode 15 Story

Castle and Beckett has conflicting side on the investigation of a wealthy woman's murder where she was killed by a nail gun. The prime suspect was the husband of the victim and an old college friend of Castle. The investigation leads to an unsolved case of Philip Westlake (Damian's father) that occurred two decades ago. In the end, Castle and Beckett solved two cases where the one who was responsible for the death of Demian's wife is her employee who wanted to solo her ex-husband. Lastly, Demain was arrested because his the one who plotted to kill his father via the help of a insane college classmate.

Who is the real killer? Will Beckett and Castle join forces to know who murder the victim? Don't miss to Watch Castle Season 3 Episode 15 this Monday night