Earth is enveloped in what seems at first to be to be a harmless cloud of cosmic dust. But it leaves behind a deadly disease, dooming every human being on Earth unless an antidote can be found. Medical experts strive to find this antidote, but have to report failure. At this stage a mysterious woman arrives from Jupiter with the antidote mankind so desperately needs, but she demands in return the services of Doctor Meadows as her mate; he will have to return with her to Jupiter to help regenerate her race, where males are extinct. Meadows reluctantly agrees, and the antidote is given, saving humanity, so Meadows prepares to accept his fate...