A brain orbiting the earth in a capsule, its human body gone, its onetime body. A novel written from the point of view of the brain told in the 3rd person close up — too close for comfort. A brain that has been surgically divorced and lifted out of that body that had been terminally ill, we will learn — an engineer who had been suffering from radiation and had agreed to be used in a solar experiment — though he is perhaps of hardly more than passing concern in a tale whose growing is here and now under light which is alive in a capsule with green growing things. A solar energy experiment that changes unexpectedly.A brain hooked up to instruments and nutrients in a space capsule, monitoring its physiological self, transmitting information along the Concentration Loop to scientists on Earth, whom it knows only by sound as the Good Voice, the Acrid Voice. Groping for words, memory, links, a grasp of what is happening to it, the brain, this stunned thing, begins to go beyond its assigned functions. It becomes more than IMP, a NASA acronym for Interplanetary Monitoring Platform. It is Imp Plus. Awakening, always awake, growing, we learn, not only as it relearns words and itself, fragments of memories from its terrestrial life and other data rich and fascinating, but growing a strange new body. When it develops an autonomous intellect and effective life and cuts itself off from ground control in the unraveling drama of this growth, what can be its fate in collaboration with the sun and still more than the sun?