Nick Nelson of the Space Patrol and his Martian gunner, Kodi, find a strange object silhouetted against Earth's Moon. It is a gambling ship called the Sky Palace. The ship is operated by a Plutonian named Jol. Patroller Nick Nelson goes aboard the craft in his spacesuit, sneaking in when the doors open to permit spacecraft of Sky Palace members. Nick gains entrance to the casino, taking up a booth there to observe the patrons. He notes Martian Space Bandits, a Saturnian Drug Smuggler, and a Mercurian Space Pirate among the revelers. The Saturnian is wanted by authorities on five planets.