Set in sixteenth-century Germany, it depicts a love triangle between Renata, a passionate young woman, Ruprecht, a knight and Madiel, the fiery Angel.
The novel tells the story of Ruprecht's attempts to win the love of Renata whose spiritual integrity is seriously undermined by her participation in occult practices.
This love triangle is now recognised to be that which existed between the author, Bryusov, the symbolist novelist Andrei Bely and their shared lover, the nineteen-year-old Nina Petrovskaya.
The Fiery Angel is generally regarded as a work of painstaking research and heightened emotion in which the author's comprehensive knowledge of the esoteric is displayed.
The Fiery Angel has been compared to Mikhail Bulgakov's The Master and Margarita for its general theme of the occult, to Joris-Karl Huysmans's Là-bas for its description of a black Mass, and to Aldous Huxley's The Devils of Loudun for its depiction of religious hysteria.