This is an agreeable adventure, somewhat more serious than Pandora's Planet. A spaceship captain of the Interplanetary Patrol responds to a damsel in distress who turns out to be a princess, the sister of the almost-adult heir to the warlord's world of the title. Her brother has fallen under the control of his ambitious regent Duke Marius, who hoes to discredit him and take the throne himself. To prevent this, the patrol captain's mind is switched with the prince's, and for a while the new 'prince' does very well at foiling the duke's plots. But when the tie comes for the prince to claim te throne by the traditional drawing a sword from a stone, he is unexpectedly declared unworthy, and has to start over as the lowest of the nobility, a plot twist I admit I had not expected. ( )