A murder on Solaria returns Elijah Baley, human, and R. Daneel Olivaw, robot, to partnership in crime hunting. Solarian life and times present difficulties to both, for human spacers are bound to a remorseless robotic society and the interpretation of their traditions and customs becomes Baley's first job. He learns to conquer his agoraphobia, he smashes through Solarian taboos — and he returns to Earth with valuable information for the future. As in Caves of Steel (1954), purposeful projection.