It is the disastrous grades at the end of the school year that make several students from different places gather at the school to spend the whole summer studying, in order to make up for the lost course. Naturally, at this school, the last thing the kids are going to do is study, but the mayor of the town wants to demolish the school to build a housing development...

Madrid, the beginning of the century. One day, the police inspector Santos Trinidad coming home very drunk, is involved in a triple murder. But there is a witness who managed to escape and that could incriminate him. Santos undertakes an investigation to locate and eliminate the witness. Meanwhile, Chacón a judge in charge of investigating the triple murder, meticulously advances in the search for the murderer. Santos and Chacon soon discover that what seemed a simple case of drug trafficking is actually something far more dangerous.