Frena.

Musa goes to the Registry Office to verify his identity, but discovers that there is no trace of him in the system: he does not exist. This raises suspicions among the officials and they convince Musa to plunge into a Kafkaesque process where he will have to go to a judge.

Four Spanish ex-intelligence officers are assassinated simultaneously worldwide. The CNI discovers all participated in the covert "Operation Ciénaga" decades ago in Colombia. Zeta, the CNI's best operative, must hunt and protect the sole survivor, facing his deadliest global mission yet. Top Colombian agent Alfa will join Zeta, seemingly knowing more about "Ciénaga"'s secrets than him.

Desirée is a young podiatry student who starts working as a sales assistant in a shoe store. She and the owner, Manuel, seem to have little in common, but they will soon discover that they are a perfect match for each other.

After the discovery of some human bones at a site, Adela and Javier, a couple of archaeologists with years of experience, have to live with the first signs of Javier's dementia and a new discovery, which like an echo, seems to resonate more and more in their daily life.

Francisco is a beggar who lives in the Almudena cemetery. One afternoon, while walking among the graves, he meets Julio, another peculiar beggar who claims to be a poet.