The story takes place inside a small alternate universe, less than a light year across, enclosed by a barrier. The fabric of the space inside this universe is white in colour, taking the form of a mist, and the “suns” are black voids (so at dawn you get “voidrise” instead of “sunrise”), which draw on the mist. It is a universe composed of thought energy, the power that holds all its matter together.
Two humans are deposited into this environment; Kasstovaal, a space pilot, and Jeryant, a medic. Their bodies, as well as the ship they were travelling in, instantly cease to exist under the alternate physical laws that apply around them. Their minds survive, however. They are rescued by the Dwellers who live in the Rock, a mountain floating free in open space. The Dwellers give them temporary bodies (Bio-forms) and introduce them to the skill of matter-forming, the ability to create any substance or object purely by mental force. It is a skill natural to the Dwellers, who are an empathic race, able to transmit their emotions and sense them in others. The Dwellers are not remotely humanoid but are able to give the humans the illusion that they are, to make them more comfortable.
But the humans discover more far-reaching differences and, worse, realize that their presence inside the mini-universe is causing the barrier around it to contract, which must eventually destroy the Rock. They resolve to escape back to their own reality as soon as possible to save the Dwellers and protect themselves. They discover a way back, using the matter-forming process, and make their preparations to leave. Before they can leave, however, one of the Dwellers tries to assassinate them.
The review of this Book prepared by David Mills