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.

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.

Marcos is attacked while Lua sleeps in her room. Aware that everyone can be a target, they assign a police escort to all the members of the Unit, who must also face the fact that there could be a mole among them.

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

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.