Jim Phelps is the head of a super-secret government agency ("Impossible Missions"), and is often given secret anonymous covert missions to attempt; quite often they are unmasking of criminals or the rescuing of hostages. He picks his team depending on which tasks need to be done. One thing is vital on an Impossible Mission: the mission must be carried out in entire secrecy, often relying on high-tech equipment and elaborate deceptions.

The plot follows the novel more closely than does any other Tarzan movie. John and Alice Clayton take ship for Africa. Mutineers maroon them. After his parents die the newborn Tarzan is taken by a great Ape, Kala. Later the boy finds his father's knife and uses it to become King of Apes. Binns, the sailor who saved the Claytons and who has been held by Arab slavers for ten years, finds the young Tarzan and then heads for England to notify his kin. A scientist arrives to check out Binns' story. Tarzan, now a man, kills the native who killed Kala; when their chief is killed the black villagers appease Tarzan with gifts and prayers. The scientist's daughter Jane is carried off by a native, rescued by Tarzan (who has burnt the native village), aggressively loved by him ("Tarzan is a man, and men do not force the love of women"), and at last accepts him with open arms.

On a warm and sunny summer's day, a mother and father take their young daughter Dollie on a riverside outing. A gypsy basket peddler happens along, and is angered when the mother refuses to buy his wares. He attacks mother and daughter but is driven off by the father. Later the gypsy sneaks back and kidnaps the girl. A rescue party is organized but the gypsy conceals the child in a 30 gallon barrel which he precariously places on the tail of the wagon. He and his gypsy-wife make their getaway by fording the river with the wagon. The barrel, with Dollie still inside, breaks free, tumbling into into the river; it starts floating toward the peril of a nearby waterfall . . .

The comfortable and amiable Daniel Boone Brown, a resident of New York's water front, becomes the victim of a mad scientist's psychological experiments. For days, Dr. Ulrich Metz messes up Daniel's life, bringing on failing health, restless sleep, a nervous and irritable disposition, tardiness for work, and superstitions that cause worry and fear. Several months into the ordeal, one of Metz's minions, hired as Daniel's livery, feeds him a midnight snack of spring onions, lobster, Welsh rarebit and mince pie. We see the contents of his stomach causing pain and distress; then he has vivid and surreal nightmares. Will Metz succeed in driving Daniel to suicide?