[1] The first season revolved around an investigation by undercover police officers Víctor Reyes (Yon González) and Laura Cortés (Blanca Romero), alongside their superior, Superintendent Casas (Lluís Homar).
In May 2015, it was confirmed that the series would have a second season, centered on a different investigation, in which Yon González and Lluís Homar would reprise their roles, with Olivia Molina playing the new main female character.
[2][3][4] In the small town of Cienfuegos, it's a very special day for 7-year-old Alicia Vega (Aroa Palacios) and her family: her First Communion.
Undercover agents Víctor and Laura arrive in Cienfuegos pretending to be a married couple to infiltrate the surroundings of the Vega family and the rest of suspects.
The fact that the disappeared girl is a French citizen will cause the arrival of a French Police inspector and an agent (Mar Sodupe and Hugo Becker) who will go undercover along with Víctor in a complicated police collaboration: frictions are frequent due to the different procedures and ways of seeing the investigation.