Allyn Vage was once a beautiful woman, but due to an accident - which may have been a murder attempt - she was now a hopeless cripple, burned and disfigured and without the senses of sight, hearing, smell, taste and touch. When they brought her to Jome Knard, that noted physician had no choice but to employ a certain apparently miraculous device, incomprehensible even to him, to keep her immobile body alive and to restore and regulate her sensory perception. This strange machine had been imported from a seemingly primitive people on the world of Akkilmar. They had allowed it to be exported, but there was something about it they couldn't - or wouldn't - explain. Little did either the doctor or his patient realize that between them they had now become the lever that could topple a world! (First publshed 1961)