The sailing ship Mary Jane is Australia-bound with a mixed company of free settlers, militia, convicts and crew when she goes down in a cyclone. During the storm, convict Billy Rose helps a boy. David, ashore on a nearby island. There they find a small group of fellow survivors — Jan Lindburg, his wife Eve and daughter Angie, a German family, an Englishwoman, Cathy Dunbar, and Sergeant Holt.
The survivors build a stockade and explore the island. The island, their first place of rescue, appears to the survivors of the Mary Jane as a prison. The castaways will soon realize that this is one of the many South Sea Islands located far away from the Australian mainland.
IRVING (Don Barkham) is the convict whose obsession with the idea of escaping to the Dutch East Indies disrupts life among the survivors.
When a storm destroys the camp and washes up wreckage from the ship, Jan salvages many useful items and discovers some gold coins.
The children, scared by islanders in canoes, run into the jungle, only to fall into an animal trap.
The castaways react with alarm when Cathy comes upon a wounded savage in the jungle.
An ongoing feud with Sergeant Holt motivates the two convicts among the castaways to establish their own camp.
When strange mud-clad islanders arrive by canoe, Irving plans to make his escape to the Dutch East Indies and trades some of the castaways' precious possessions for a suitable boat.
Irving tries to prevent the castaways from burning a beacon to signal a passing ship.
David befriends a young islander who is being chased by two fierce warriors of a different tribe.
David and Angie get lost near a crocodile-infested fiver,
The water supply dries up, and only Irving has an adequate supply.
The castaways are growing despondent, and Billy Rose finds clues to a former settlement.