Bob Russell e Joe Thomas are a couple of inmates in a grimy Latin American prison, run by the cruel Captain Delgado. The two manage to escape from prison and assume the identity of two friars from Rome (respectively, Father Orso and Father Zaccaria), destined for the mission of San Rolando. Here the two discover that some girls from the village have mysteriously disappeared in the city, while looking for a job. While investigating, they discover that the girls are victims of a criminal organization, in which Captain Delgado and the village shaman are also involved.

Father Campana tasks "Fathers" Orso and Zach to sell village-made potteries into the city to cash in with local businessman Don Medina, sending Father Raphael to watch over them. The two convicts-turned-priests take advantage of the situation, and plan their escape at the expense of Don Medina. Between a failed robbery and a confrontation with rebel leader Napoleon, Orso and Zaccaria expose Medina’s dirty affairs, retrieve the money, but ultimately fail to take off.

Father Raphael returns from his sabbatical in the jungle with the Niquoias head-hunter tribe, who (according to native lore) have the duty of guarding the true location of Eldorado. Raphael’s landscapes resemble the descriptions of Eldorado itself - but this becomes apparent only when the paintings are sold to rich heiress Michela, whose father spent his final days in search of the mythical place. Michela’s uncle Graziani and his ruthless henchman Rupert kidnap Father Raphael to force him to reveal where Eldorado is, bringing Orso and Zach to free their brother - and possibly recover the treasure.

A plane carrying the young Wolfgang Galveston III, son of a wealthy Latin American millionaire, crashes near San Rolando mission. The millionaire's son promises "Fathers" Orso and Zach a lot of money if they help him out of the jungle, and the two of course agree. However, corrupted Captain Delgado also gets wind of the crash, and goes in search of the young boy to obtain a ransom.

A group of boy scouts finds gold in the river near the mission of San Rolando. News gets to unscrupulous businessman Alfonso Santillana, who tries to evict the mission and take the gold for himself. While "Fathers" Orso and Zach take up the fight to save San Rolando, it is also the opportunity for Orso to settle an old score with Santillana, who was the one who put him behind the bars with false accusation ten years prior.