This is the story of Mariano Gavín's life and feat, known as The bandit Cucaracha. His life was dramatically changed for ever due to a controversial event with one of his "friends". Chased by the Civil Guard, Cucaracha was forced to become a bandit and to be hidden in the most remote and unspoilt places in the Monegros region in order to keep alive. Mariano and his band go through a series of robberies, ambushes and riots in their aim to steal from the rich to give it to the poor. Little by little, his band becomes strongest and his achievements are widely-known, so the Civil Guard takes matters into their own hands with the intention of capturing the bandit Cucaracha.