Eros at Zenith — Mike Resnick

Book Two of the Velvet Comet—the enormous, exclusive, elaborate, and infamous orbiting brothel...

Arrogant and overbearing Syndicate detective Andrew Crane arrives aboard the Velvet Comet to investigate a murder. When Crane discovers that the murderer is setting a trap to lure a notorious criminal aboard the Comet, the consequences of solving the mystery forces Crane to become judge, jury, and executioner.