June 18, 1961. In a small village in Northern Spain, San Sebastián de Garabandal, four girls, Conchita, Jacinta, Mari Loli, and Mari Cruz, claim that St. Michael and the Virgin Mary have appeared to them. The village's parish priest, Fr. Valentín, and the Civil Guard brigadier, Mr. Juan Álvarez Seco, suddenly become protagonists in an overwhelming event.
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.
