The Zero Stone — Andre Norton

A mysterious stone, born of worlds long extinct, is the key to powers unimaginable to man -- powers that could enable its owners to control the universe. Murdoc Jern, gem trader, finds that possession of the stone has led him to the center of a web of intrigue and murder.

With his companion Eet, an inscrutable feline mutant with phenomenal ESP powers, he is hunted through space, coming finally to a long forgotten planet inhabited by apelike "sniffers." There, facing the predatory sniffers, the antagonistic Patrol and the laser-guns of the Thieves' Guild, Murdoc must seek the source of the Zero Stone and bargain for his right to pursue his destiny as a free man.