Castle and Beckett need to uncover a gunman's agenda after he takes hostages, including Esposito, on the subway.
Callen and Sam's new murder suspect is a retired assassin they came across on their first case together. As the two head to Mexico to find him, Deeks and Nate help out the investigation in Los Angeles.moreless
While Wade gets advice from Jessica on winning Marion back, Stuart gets to know some construction workers.
The squad is pulled into a city-wide investigation of sniper attacks against police when a lead links Fin to the case. Lt. Eames adds her expertise as they scramble to identify the suspect from Fin's time in Narcotics.moreless
With Nikita trapped and drugged, Amanda subjects Nikita with her horrific mental conditioning process, sharing terrible memories of her own childhood with Nikita. Through the conditioning process, Nikita uncovers Amanda’s deepest, darkest secret. With Alex's role as the leader of the mutiny now out in the open, she struggles to save everyone at Division as the violence escalates. With Michael locked up at the hands of Division members, Birkhoff and Sean work to save the women they love. Meanwhile, Owen's recent discovery of his lost memories drive him to take startling actions during Division’s lockdown.moreless
Alex admits to Birkhoff her hope of leaving Division, and Amanda starts to provide Owen with the troubling memories of his real past. Despite Nikita's efforts to help, Owen begins to confront the events of his past in the military.moreless
Nikita and Michael hear about a new prosthetic hand that could allow Michael to return to his former self, but obtaining the hand will come at a steep price. Meanwhile, Alex and Sean work to track down the agents inside Division are beind a mutiny, which ends in bloodshed.moreless
Betrayed, left with no other option but to run, the crew of the USS Colorado will have to fight for its survival.
Serena loves her new job in Hollywood, but makes a mistake trying to impress her boss. Chuck and Nate arrive in LA as their last stop of their Lost Summer trip, joining Serena at a glamorous party, where Nate meets a sexy older woman. Blair and Louis return from Monaco and begin planning their royal wedding, but when Louis refuse to support Blair's decisions against his family, their relation is at risk. A magazine is planning to run an excerpt of Dan's book until an unlikely ally helps him.moreless