Two skeletons are found in a reservoir after it dries up due to a severe drought in the border village of Campomediano. Three people from either side of the Portugal-Spain border start investigating the mystery behind this gruesome crime.

Information from one of Oscar's confidants brings up questions about Ortiz's potential involvement in the disappearance of two activists; Daniela and Helder travel to Portugal.

Daniela's investigation leads her to believe that Ortiz visited Antonio's house before his death; Daniela and Helder meet to exchange evidence but are ambushed by an unknown man; Amalia thinks that one of the victims was her son Joaquim.

Amalia's suspicions about the corpse belonging to her son are proven true. She tells Daniela and Helder that Joaquim was dating Paula, but a revelation about his sexuality makes them question the legitimacy of this information.

Investigations into Sanjurjo and his involvement in the case continue while Martin applies more pressure on him; Paula learns that her father is sick and asks Amalia to take her side against him.

The gun found in Antonio's house is believed to have come from the police station; Oscar receives a series of threatening messages; Luis makes some organisational changes that sideline Paula.