Commissioner Leon (Miguel Angel Landa) investigates the murder of a woman in a population near the capital. The woman was raped before death and the case is complicated when his brother becomes the prime suspect, since it is a priest (Eduardo Serrano). Because of the implications that inquiries might have, Leon is pressured to keep the event as a "crab" (Cangrejo, or a unsolvable case), but he decides to comply with the law.

Fulgencio Martinez wants a car to give a good image to the president of the company where he works and thus get a promotion. Carmina, his wife, suffers from a fatal illness and the only way to flatter her life is with an operation. Martinez tries to kill her so as not to spend the money from his savings on the clinic and buy the car. In the end, after a dream that makes him feel the loss of his wife, he abandons his plans.