Having just returned to Earth from an intergalactic research mission, Professor Peter Maxwell, specialist in Supernatural Phenomena, finds himself in desperate straits. Earth, as he is aware, is well advanced in many areas; perfected time travel, for instance, enables all creatures (goblins, dinosaurs, and Shakespeare!) to coexist. But Maxwell has accidentally discovered a mysterious crystal planet containing a storehouse of secret information not yet known to Earth. Knowing the value of the p