On a tramp steamer off Central America are Mr. and Mrs. Sheppard, five prisoners en route to a Nicaraguan prison, and Corbett, an American carrying money for a Honduran counter-revolution. Denied permission to land in Honduras, Corbett releases the prisoners and with their aid hijacks the ship. They land, taking the wealthy Sheppards as hostages, and start the arduous trip upriver to Corbett's rendezvous, meeting jungle hazards
The residents of a small town are excited when a flaming meteor lands in the hills, until they discover it is the first of many transport devices from Mars bringing an army of invaders invincible to any man-made weapon, even the atomic bomb.
John Vickers has spent eight years hunting for the three men who murdered the woman he loved. He finds one, Woodson, and kills him in a gunfight, but not before learning that the other two men have joined the U.S. Cavalry.
A doctor hunts a vicious, man-eating tiger that terrorizes a native jungle village. In time the doctor experiences a personal change when he accepts their native customs and beliefs.
