Night and Day

When performing an autopsy on the charred corpse of a car crash victim, respected forensic pathologist, Sara Grau, recognizes a familiar tattoo on the burnt body: it is identical to the tattoo of a man she had a one-night stand with only a few weeks before.

As the Granny Killer follows Sara and Lluís to the hospital and is recognized by Sara as the man she had a one-night stand with, the police discover their first lead. Sara, however, is unaware of her previous tryst's connection to the recent spate of murders in the city.

Figuring out the connection between the car crash victim and her one-night stand, Sara continues to pursue her own investigations, and the police believe they have identified the serial killer terrorizing Barcelona.

A sudden twist sees the chief suspect in the recent spate of killings, firefighter Marc Ramos, being hailed as a hero for saving a woman's life. Meanwhile, Lluís and Clara fly to Tangiers on a business trip together.

The Granny Killer claims his fifth victim and Judge Cases comes under mounting pressure from the public to catch the killer. Performing an autopsy on the fourth victim, Sara notices a strange mark around the victim's mouth...

Unaware that her lover is Marc Ramos, the Granny Killer, Sara confronts him for following her. Meanwhile Judge Cases' wife continues to threaten blackmail, leading him to make a drastic decision.