
When Sara comes into possession of an incriminating video of Ramos torturing a prisoner in Iraq, instead of taking the footage to the police, she first takes it to Ramos' mother in an attempt to make her realize what kind of monster she is protecting.
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.