Hard-working, often enjoyable science-fiction consciousness-raiser--something like Cat's Cradle meets Network meets Stranger in a Strange Land. Fantasist Godwin (The Last Rainbow; A Truce with Time) refurbishes an old, old notion. Barion and Coyul, pure energy beings from a vastly superior civilization, are stranded on Earth in the Pliocene. With nothing better to do, they decide to improve the humanlike apes of the epoch--the upshot is ourselves. But now Charity Stovall, an appealing, potentially intelligent young woman stultified by her mean small-town upbringing, is about to marry the hate-filled, mediocre fascist Roy Stride; a child born of this union would make Hitler look like a democrat. So Barion, who runs Topside (Heaven), and Coyul, in charge of Below Stairs (Hell), decide to interfere once more. They snatch up the astonished couple, convince them they're dead, and whisk them to Below Stairs. Here, Roy becomes the swaggering, jackbooted SS-type he always dreamed of being, while Charity's eyes are opened and her mind educated in more subtle and often amusing fashion. Finally, Charity realizes what an appalling error she's made; Roy is shown just how mediocre he really is; the galactic bus shows up for Barion and Coyul; and everything works out, more or less, in the end. A familiar outline, fleshed out with some razor-sharp detail and peopled with believable characters: Godwin's best so far.