After confirming that there is a mole, some arrests are made. But new obstacles appear in the Unit's investigation.

An attack puts Carla's team to the test, as they have to face unforeseen consequences and which they must face without support from the authorities.

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 Unit manages to bring the children of the main suspect to Spain to put pressure on him. The search for the possible mole stalls

Carla finds out that there are certain political forces, pressures and scheming at work to replace her as leader of the case and head of the Unit.

In Kabul, the clock ticks down as the last flight will leave within the hour, but the Taliban have taken Fazela hostage as retaliation for Carla's betrayal, while Marcos seeks his escape by a land route.

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.

Miriam and Marcos make it to the home of one of Massoud's contacts. Massoud is able to call Fazela, who makes it through to the Spanish to tell them their whereabouts. Carla resorts to a ruse to get to 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.

Melilla. Tangiers. Toulouse. In the dark of night, officers from the Spanish, Moroccan and French police forces carry out a synchronized anti-jihadist strike but retaliation looms.