In the twenty-first century, a battered world is ruled by a crafty old tyrant, Genghis II Mao IV Khan. The Khan is ninety-three years old, his life systems sustained by the skill of Mordecai Shadrach, a brilliant young surgeon whose chief function is to replace the Khan’s worn-out organs. Within the vast tower-complex, the most advanced equipment is dedicated to three top-priority projects, each designed to keep the Khan immortal. Most sinister of these is Project Avatar, by which the Khan’s mind and persona are to be transferred to a younger body. Nominated for Nebula Award for Best Novel in 1976. Nominated for Hugo Award for Best Novel in 1977