In the year 1999, shortly after an early warning system is established on the moon to repel alien invaders, a radioactive chain reaction blasts the moon out of its Earth orbit. Three hundred men and women are marooned as the moon slowly begins to drift in space, seeking a new planet to which to affix itself. Considered invaders by the inhabitants of other planets, the marooned Earthlings struggle to combat the life forms of distant worlds, the elements of outer space, and sustain life on their new world in its odyssey across the universe.