Following the events of The Sheriff and the Satellite Kid, Sheriff Hall and H-725 (using the official identity of Charlie Warren) still get no rest from the military - because the little alien has not yet grasped the meaning of keeping a low profile. They are constantly on the move, and H-725's father has had to pick them out of a tight spot too many times already.

The town of Newnan are seeing little green men everywhere. The military have arrived and are on the lookout for UFOs. Everyone's high strung and Sheriff Hall (Bud Spencer) is left to deal with the aftermaths of the hysteria. On his way home from patrol he happens upon a little boy claiming to be an alien by the name of H7-25. At first the sheriff doesn't believe the boy, but with the mounting evidence, even he must eventually concede. Soon the military is after Sheriff Hall and H7-25, and it is up to the sheriff to keep the boy safe and beat up large swaths of soldiers so H7-25 can go home.

A master thief, just out of prison, concocts a risky final score that would net him over a million dollars.

Bandit Gordon frees a group of prisoners, forcing them to join his gang or die. Arizona Colt, declining to do either, heads for Blackstone City where Gordon is planning a robbery. When one of Gordon's men murders saloon girl Dolores, Arizona offers to hunt down the killer for the price of five hundred Dollars and Dolores' sister, Jane