The film begins with a school teacher bidding farewell to his students, who are leaving for the summer. As he is heading home he notices two of his students are hitch-hiking and picks them up. He invites them over for dinner and lodging, which they accept.. The majority of the film from this point on is set at the mansion, where the two students turn from guests to prisoners under the teacher's command.
Trini is the daughter and granddaughter of thieves. Before it was a specialist in the art of opening safes, but one day decided to change their way of life and is now a cashier at a supermarket. It has also taken a law student boyfriend, but all will be dashed when his father stop, Mr. Baldomero, for stealing 36 kilos of appliances.
