The team searches for a sniper who is terrorizing New York; Beckett tries to hide her worsening PTSD from Castle and the detectives.
Addison has an ovarian cancer patient that doesn't want surgery because she wants to have her own child; Charlotte opens up her own practice leading to a battle for patients; Pete and Sam work on a cyclist's sore knee but ignore his potentially fatal heart condition; Dell convinces the practice to try an adoption matching service.
Jim's friend Matt returns home with memory loss after serving overseas in the military where all of his friends died. Matt's comrades appear to Melinda to help Matt regain his memory.
When men across the country turn up dead, the team investigates a deadly gambling ring that is running a high-stakes Russian roulette tournament. Also, Don and Charlie become concerned about Alan's financial health.
When the suspected murderer of Beth's boss at Buzzwire kidnaps her, Mick's brief encounter with mortality is in jeopardy.
