Dion Fortune's first magical mentor was the Irish occultist and Freemason Theodore Moriarty. She had befriended him while still involved in psychotherapy, believing that he could help one of her patients, a young man who had been fighting on the Western Front and claimed to be plagued by unexplained physical phenomena.

Moriarty performed an exorcism, claiming that the young man was the victim of the soul of a deceased East European soldier which had latched onto him as a parasite. Fortune became an acolyte of Moriarty's Masonic-influenced lodge, which was based in Hammersmith, and joined his community of followers living at Gwen Stafford-Allen's home in Bishop's Stortford.

Moriarty spent much time talking about the lost city of Atlantis, a topic that would also come to be embraced by Fortune. Fortune later fictionalized Moriarty as the character Dr.

Taverner, who appeared in a number of short stories first published in 1922, later assembled in a collected volume as The Secrets of Dr. Taverner in 1926.

Like Moriarty, Dr. Taverner was portrayed as carrying out exorcisms to protect humans from the attacks of etheric vampires.

. .