In a fifteenth century English town, Bert, a poor kleptomaniac, pilfers the carriage of the coach on which he and his partner Bob have been sneaking a ride. Bert and Bob are caught and are locked in the village stocks. There, they are pelted with vegetables, until Mary Ann, a young commoner who has disguised herself as a stableboy in order to avoid marriage to the aging Duke of Weskit, rides by and helps them to escape. The trio arrive at an inn where the duke's boar-hunting nephew, the Baron, is dining. Penniless, Bob and Bert concoct a plan to eat without paying, but are pleasantly surprised when Mary Ann announces that she has one hundred sovereigns. Made generous by Mary Ann's cash, Bob and Bert treat all of the inn's customers to food and drink. As they are about to pay, however, Bert is overcome by his kleptomania and steals not only Mary Ann's money, but the innkeeper's as well. To flee from the innkeeper and Andrew the Jailer, who has tracked them from the stocks, Bob and Bert overwhelm two wealthy men and exchange clothes with them. In the men's coach, Bob and Bert discover a letter that identifies their counterparts as the king's physicians. Although Mary Ann is dismayed when the coach delivers them to the duke's estate, Bob happily introduces himself to the Baron's beautiful wife, Lady Genevieve, and proceeds to administer to the duke, who has been suffering from insomnia brought on by Mary Ann's humiliating disappearance. In spite of their ignorance, Bert and Bob "cure" the duke and ingratiate themselves in his household. That night Mary Ann kisses Bert impetuously and reveals her disguise and her predicament. While Bert dedicates himself to Mary Ann, Bob flirts with Genevieve until intimidated by the threatening growls of the Baron's dog, Brutus. The next night, however, Bob forces Brutus to accept him, unaware that the Baron has trained the dog to reveal, by his friendliness, any man who has become intimate with his wife. When the Baron returns the next day from his boar hunt, Bob's flirtation with Genevieve is thus exposed by Brutus. Although furious, the Baron stifles his violent jealousy out of respect for the king. Later, at the duke's betrothal party, Mary Ann overhears the duke threatening her father with money demands and, to save him, sheds her disguise and accepts the engagement. During the party, Black Devil, a wild boar whom the Baron has been stalking fanatically, is spotted in the area. The Baron offers 5,000 sovereigns to anyone who catches the boar, but as Bert nobly accepts the challenge, the king's physicians arrive and reveal the duo's ruse. After a prolonged chase involving both the Baron and Black Devil, the duo finally capture the boar and win Mary Ann's freedom.