When two Federation diplomats go missing on the planet Kaùsan, in the Triangulum Galaxy, Marc and Zyrah McGregor, along with an old nemesis, Judge Advocate General Craig Larson, must join forces to rescue them before the two are infected by a mind-wiping virus and their bodies taken over by an alien intelligence. Will they be in time? And can Marc and Zyrah prevent JAG Larson from discovering the illegal nanomedical robots, which he thought were destroyed, are still living hidden inside the McGregors?Queen's Gambit is the sixth book in the McGregor Chronicles series, which follows the amazing adventures of three generations of the spacefaring merchant family,