Prokofiev, "The Fiery Angel"

In a run-down inn, Ruprecht hears cries of fear: He finds beautiful Renata – alone. She tells him her story: Ever since she was a child she loved a fiery angel called Madiel, but she has lost him and is now looking for him, pursued by demons. Ruprecht falls in love with her, but she only manipulates him. He follows her through a strange land. After she enters a convent, strange things happen there. An exorcism spirals out of control. In the end Renata shall be burned at the stake. What is illusion or reality? Who is insane in this story?