Zapa is a locksmith in a quiet and little town lost somewhere in the province of Buenos Aires. The work is quite slow, and hours seem to pass slowly. Polaco, the owner of the shop, sends him on a job that consists of opening a safe at an office. The next day, Zapa is imprisoned for being responsible of robbing the place. Ismael, his uncle, a retired policeman, bails him out and sends him to Buenos Aires. Zapa becomes an aspiring officer in the Buenos Aires Police. He gets to his new home city, takes the instructional course, works at a precinct, has a love affair with a teacher and starts to see his life turn into a strange fiction.