After more than a year of intense searching, the unit led by Chief Commissioner Carla Torres has arrested one of the most wanted jihadist leaders. But this operation sets in motion a revenge plan against the members of La Unidad.
The unexpected disappearance of Myaz sets off the alarms at the Unit. Their spy was based in Salt, near Badalona (Catalonia), so Marcos focuses his team's efforts in that region.
Miriam finally succeeds in setting up a meeting with the informer of the CIA who had seen Al Garheeb in Nigeria. She flies to Lagos where she meets the man in question: William, an arms dealer.
Marcos heads the party that searches for the two terrorists all over he area. Now that the fugitives no longer have any weapons or any logistic support, he thinks that they'll soon catch them.
Lack of resources and pressure to catch terrorists increases tensions within La Unidad, whose members also have to deal with the personal problems caused by their exhaustive dedication to police work.
Touched by the revenge unleashed against them, the members of the Unit look for a way to protect themselves while going after the members of the terrorist cell, who have not yet completed their plan of attack against Carla's team.