Synopsis: Four men and a girl crash land on the red planet after their rocketship suffers severe damage in a meteor storm. Once on Mars they discover an advanced civilization living in vast underground cities. Seemingly benevolent, the Martians welcome the Earthmen with open arms and offer to assist them in repairing their rocket. But all is not as it seems. A sinister plot is uncovered that could mean the annihilation of invading Martians!