A nuclear power plant in Spain suffers a meltdown, causing hundreds of fatalities and the creation of an exclusion zone; on the third anniversary of the accident, a man is found murdered and cannibalized.

When a federal agent is assigned to their case, Héctor and his partner, Martín, wonder if he is there to help solve the killings or cover up what they increasingly think the local government is trying to hide.

Guilt-ridden by the mistakes made at the meltdown three years ago, Julia takes action when contamination levels at a school suddenly surge.

As it becomes more obvious that the company in charge of decontaminating the zone is engaged in dirty dealings, Héctor and Alfredo are sure it's a key to the case.

While solving the murders, Héctor, Martín and Zoe form a pact to keep important information secret; Héctor continues to uncover the conspiracy behind the decontamination of the zone.

Héctor and Julia continue to close in on the answer to the question of why the decontamination company has been hunting down five of its workers who fled from their corporate apartments just before the first killing.