Six years after murdering his parents, Sergio gets released from juvenile detention and becomes the subject of Ana's secret investigation.

Marta puts her relationship with Eneko at risk by getting closer to Sergio, who opens up about life before the death of his parents.

Sergio returns to the detention center and has an unexpected encounter there. Thanks to Marta, Ana discovers information that may turn the case around.

When the investigation wavers, Ana discovers that she and Sergio share more in common than she thought. A determined Sergio tries to find his sister Noa.

Pressure from Cabrera forces both Sergio and Greta to make desperate moves. Eneko tries to reconcile with Marta. The case threatens Ana's personal life.

Ana turns up at Sergio's house, and he insists on meeting Noa. The police try to close the case for good while a leak exposes Cabrera's methods.