In Palestine, during a truce in the Third Crusade, Sir Kenneth, a poor Scottish knight, fights a Saracen emir beside the Dead Sea and ends the day riding with him as a friend. King Richard the Lionheart lies sick with fever in the Christian camp, and a learned Arab physician, El Hakim, arrives to cure him with a talisman. Meanwhile the princes of the crusade quarrel and plot, Kenneth is disgraced when the banner of England is torn down from the mound he guards, and only at the end are the true faces of the emir and the physician revealed: both were Saladin.