Lisander tells Roscille that his father was once a brilliant king who loved his queen. Hunting in the forest, he saw a beautiful doe that, strangely, had horns. When he shot it, the arrow wounded it but also circled back and wounded him. The doe turned into a woman, whom he raped. She cursed all the firstborn sons of his line and then died. As a consequence, Lisander turns into a monster when he sleeps and has to be locked in a stone room. Evander was born fully human, but their mother died in childbirth, and with this loss, Duncane became sick. He hunted down all the witches in the kingdom, but they all agreed only the witch who cast the curse could undo it, and she was dead. 

Roscille says that all men are monstrous; she prefers that Lisander’s physical form is honest. However, Lisander can no longer stay awake, and he turns into a serpentine dragon, ripping open the cell bars. He lands on her for a moment, exciting her, but then flies out of the castle.

Banquho sends Senga rather than a physician to treat Roscille’s wounds because Roscille’s enchantment does not work on women.