The Naked Sun, Isaac Asimov, Street & Smith Pualications, 1957, 196 pp
This is the sequel to The Caves of Steel, again featuring Detective Lige Baley and his robot assistant R Daneel Olivaw. They go offworld to investigate a murder on Solaria, one of the 50 Outer Worlds inhabited by humans.
Solaria's most eminent scientist has been found dead and it appears that he was done in by his wife. The planet has something like 200 robots for every human, similar to the slave/master populations of certain ancient civilizations. These robots are all under the Three Laws of Robotics as laid out in I, Robot, but there is an uneasy feeling on Earth about ominous rumors coming from Solaria, so Bayley is also serving as a spy.
Despite his unreasoning fear of the naked sun after living his entire life in the steel caves of Earth, Bayley's professional skill soon has him flaunting all protocol on Solaria. He finds the murderer of course but also a much more deadly character.
I thought The Caves of Steel was better as far as storytelling and suspense, but Asimov has the detective genre nailed and his futuristic observations are as brilliant and icily witty as always.
(The Naked Sun is available in paperback by order from Once Upon A Time Bookstore.)