Detective Kevin Ryan is moonlighting at his brother-in-law Frank's security firm. Ryan is taksed with protecting Congressman Lopez during a red carpet charity event. During the event, shots are fired and Lopez is shot and the woman he is speaking with, Carolyn Decker is killed. Ryan is there when it happens but he can't stop it. He chases down the man he believes to be the shooter but can't catch him. Beckett and the team at the 12th precinct become involved in the murder investigation.

They track down, Eric Chambers, a French blogger who hated the Congressman and is the man Ryan was chasing. They arrest Eric but he says he’s being set up. A hotel employee saw Eric and billionaire Carl Shelton talking about taking Lopez down just before the shooting but Beckett have no proof to back up that this is a conspiracy.

Later, Ryan realizes that Eric couldn't have fired the shots. He calls Castle in the middle of the night to share his crazy theory but Ryan may not be happy when the investigation hits too close to home.
Watch Castle Season 7 Episode 18 Online right here at TV Fanatic.