S1, E4: Alicia and Pablo go to the lake. Pablo believes Sara to be affected by the strange phenomena, like Nacho, Ramón, Esther, and María. As the days go by, more neighbours begin to exhibit strange behaviour. Ana sneaks into Nacho's house, who Pablo notices is acting more and more different. Before being discovered, she grabs a sample of Nacho's hair. Abel sees his grandfather in the distance talking with Nacho. Both turn their heads towards Abel, who can't understand why his grandfather is lying to him. María wakes up in the morning on a bench in the town square, confused, disoriented and wet. She doesn't know what's happening. Her pregnancy is also strange. She decides to install a camera in her room to find out what happens every night. She is shocked to see herself getting up in the middle of the night, leaving the room and coming back with two fish in her hands that she eats while pouring a water bottle over herself. Daniela finds a body in the lake. It's the water treatment plant technician, who measured the water quality. During the night, Ramón gets up from his chair and enters his son's room... and then cries out in pain.