Nine-year-old Hal traces a frantic S.O.S. to a group of friendly space aliens held captive inside a mountain by the evil Ness who plan to take over the world.
The new edition has been illustrated by Michael Gilbert.
Andre Alice Norton (1912-2005) was an American science fiction and fantasy author (with some works of historical fiction and contemporary fiction) under the noms de plume Andre Norton, Andrew North and Allen Weston. Norton published her first novel in 1934, and was the first woman to receive the Gandalf Grand Master Award from the World Science Fiction Society in 1977, and won the Damon Knight Memorial Grand Master Award from the Science Fiction and Fantasy Writers of America (SFWA) association in 1983.
Andre Norton. Wikipedia.