Pope is shot and killed while undercover, and it was Castilla himself who sold him out. Through a series of flashbacks we find out how and why he went undercover for the last three months, and that Elo is pregnant again.
Casqueiro assumes temporary command of the Station. An inspector from the Ertzaintza comes from Bilbao to assist in the serial-rapists case, and a corpse is found after twenty years when a retirement home is demolished.
Clara and Lucas, in her last case before she leaves the force, investigate the death of a soldier's wife who went missing a month ago. Charlie and Pope investigate a murder possibly related to a real state fraud.
Everyone at the station is shocked by Clara's death, especially Pascual. The trail of her murder at the hands of a minor leads to the discovery of two other bodies and an illegal arms dealing operation.