The Hostage of Zir — L. Sprague de Camp

Outside the walls of the starport Novorecife, Earthmen on the warrior planet Kishna are on their own. So when he is chosen to lead the first ersuma (Earth-tourists) through the sorcerer-kingdoms of this ""protected"" medieval world, Fergus Reith must first learn to speak Durou; must take the chemical oath against imparting technical information; and must above all else learn to handle a broadsword!

All these skills are needed when Reith finds himself and his ersuma trapped as pawns in a deadly war between a sorceress and a sterile kingdom under three moons … The Hostage of Zir is the third of L. Sprague de Camp''s Krishna book—interplanetary romance in the tradition of Edgar Rice Burroughs'' Martian Tales.