In England in 1912, Hank Martin, an American blacksmith, visits the Pendragon castle and tells Lord Pendragon, who is laid up with a head cold, the story of how he fell in love with Alisande La Carteloise, whose portrait hangs on the castle wall. Years earlier, in Connecticut, Hank is knocked out in a storm and wakes in the year 528 A.D. He is immediately seized by a dim-witted knight named Sagramore and brought before the aging King Arthur of Camelot, who has a head cold. Sagramore accuses Hank of possessing demonic powers, and Merlin, the king's wicked sorcerer, orders him killed, although Alisande, the king's beautiful niece, pleads with her uncle to spare the handsome stranger's life. Hank escapes being burned at the stake by focusing the crystal from his pocket watch on the sun, thus starting a fire that ignites Merlin's robe. Believing that Hank has supernatural powers, the king grants him the terms of their surrender: That Sagramore be made Hank's squire; that Hank be given a humble blacksmith's shop; and that the king host a ball in his honor. Hank is dubbed "Sir Boss," and at the ball, he and Alisande fall in love, as he teaches her to wink. She is betrothed to Sir Lancelot, however, who is a brave warrior and knight of the round table. Lancelot returns to Camelot and challenges Hank to a duel; the winner will marry Alisande. Hank uses his little horse Tex and a lasso to defeat Lancelot, but Alisande is furious at him for humiliating Lancelot and refuses to marry him. At his blacksmith's shop, Hank builds a pistol and is visited by a young peasant girl who says her father is dying of the plague. By the time Hank arrives, the man is dead. The mother then explains that her two sons have been imprisoned for a crime they did not commit. Hank convinces the king to take a tour of his country disguised as a simple yeoman so that he may see the true suffering of his people. While he is away, Merlin, Morgan Le Fay, the king's wicked niece, and the evil Sir Logris plot to usurp the throne. Sagramore, Hank and the king are kidnapped and sold into slavery to Merlin. Alisande arrives to save them, but is herself jailed. After Sagramore kills a guard, Alisande, Hank and the king are sentenced to death for Sagramore's crime. Alisande gives her amulet to Hank and pledges her eternal love. Just before they are to die by the chopping block, Hank predicts a solar eclipse after consulting his copy of The Farmer's Almanac , and when the sky goes black, they escape. Hank races to Merlin's tower to save Alisande and shoots a guard. Back in the present, Lord Pendragon tells Hank to go down to the castle balcony. There he finds Alisande, Lord Pendragon's niece, who winks at him.