."THE SUPREME FANTASY GENIUS!" That's how The Encyclopedia of Science Fiction and Fantasy hails A. Merritt, author of The Lightning Witch. Isaac Asimov simply describes him as, "The most famous of fantasy writers." In this visionary writers controversial magnum opus, a small band of explorers--including the famed Dr. Goodwin, Ruth Ventnor, her brother Martin, and the scientific adventurer Alvin Drake--finds itself face to face with a sentient, collective intelligence composed of billions of living geometric metallic forms! Spawn of an alien race that moves among the stars, seeding their kind on likely planets, the metal being intends to replace all biological lifeforms on Earth.