Pilar and Juan are a happy married couple with very few resources. One day they decide to play Christmas Lottery. But Pilar purchase tickets behind her husband's back for a raffle of a lamb, which eventually she ends up winning. Their children are delighted with the new animal, although Juan, disappointed, complains about money.Then they decide to serve the lamb in Christmas dinner, which seems impossible because children are fond of the animal and no one is able to kill him. The same Christmas Eve someone steals the lamb and, distressed for the loss of the animal, who they already loved as a member of the family, begin to look desperately to get their new pet, living an incredible odyssey in the meantime.