Castle, Season 3, Episode 24, Knockout
A manhunt is launched for professional hitman, Hal Lockwood, after he escapes during a court hearing. Lockwood possesses information about the murder of Beckett's mother. As the hunt proceeds, Castle and the team find there's someone with connections to law enforcement who's linked both to the death of Johanna Beckett and to Lockwood's escape. The season finale leads to a highly emotional and deadly conclusion with the search for Lockwood and his co-conspirator.