As Luisa, María and Rai question Carmen, whose younger sister was found drowned in a bathtub, they become suspicious the woman is hiding something.

Tensions flare between the detectives when an interrogation ventures into morally ambiguous territory regarding a suspect personally connected to María.

When detectives interrogate Isabel, she talks about love, sex and her Dalmatian, forcing Chief Inspector María to take a risk to try and solve a murder.