To prevent civil war among brothers over the succession of the throne, the numerous sons of the king of Abyssinia were required to live out their lives in the Prison of Princes, unless they were chosen as the king's successor. The least likely to be chosen was Michael, the brother of Princess Mariam, becuase he had no clansmen or influence at court.

Mariam and two faithful servants plot secretly to free Michael, but then have to alter their plans to rescue Michael in a different way when he is chosen as the king's successor.