Diego and Jeanette, a newly married couple, go to a castle, owned by Diego, to spend their honeymoon. At dusk they enter and find a corpse. Suddenly, the lights go on and they discover that the authors of this distasteful joke are several of Diego's friends. The girl suspects that there is something abnormal in that group. Little by little, the jokes are interspersed with murky affairs and unexpected murders. The commissioner in charge of the case isolates them in the castle with the intention of finding the criminal.