Two women among the few thousands living in space are targeted by the masters of the regimented billions still surviving in underground cities on Earth. They think the women constitute a threat to them.

The Impact of a comet has driven a pitifully small number of pioneers off the Earth to ensure the survival of humanity. They have peopled the nearer planets to diffuse the danger of yet another Impact, but the end is still in doubt. The first Impact's devastation has scarred all the survivors irretrievably.

It is not a fight the two women welcome. Sometimes, though, you can't step out of the way.