Version of the play "Todo bicho de uña". It tells the story of revenge. The tour of the Andean, for ten years, a young man in search of the rapist and murderer of his mother, takes us into the underworld strata fairs and circuses villagers.
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.