Helena, the low-born ward of a French-Spanish countess, is in love with the countess's son Bertram, who is indifferent to her. Bertram goes to Paris to replace his late father as attendant to the ailing King of France. Helena, the daughter of a recently deceased physician, follows Bertram, ostensibly to offer the King her services as a healer. The King is sceptical, and she guarantees the cure with her life: if he dies, she will be put to death, but if he lives, she may choose a husband from the court.