The action is set in sixteenth century Germany. At its centre is the history of the young woman Renata, who obsessed with an angel of fire. She thinks that she has been in love with him since her childhood. Renata had met Heinrich von Otterheim. Convinced that this was her angel, Renata immediately gave herself to him, but later Otterheim left.
Renata begs Ruprecht, a knight who loves her, to help her search for her “angel”. Although she thinks that her desire is inspired from above, the appearance of doctor Faust, Mephistopheles and different demons say otherwise. Her obsession turns her and Ruprecht in a wilderness of occult. After many strange adventures Ruprecht has saved his life, and Renata has been sentenced to death by fire.