Dark Piper
Vere Collis and his friends were exploring caves on the planet Beltane when they were trapped by powerful explosions on the surface. They wandered underground for days, then found a way to the surface and emerged to find that only strange and deadly mutant creatures now roamed the surface. Where were they the only humans left alive on the planet?
Andre Norton
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.
Dark Companion
Dark Companion consists of two primary books, and includes one additional book that complement the series but is not considered mandatory reads. The current recommended reading order for the series is provided below.