She collaborated with Australian writer Rick Kennett on the collection No. 427 Cheyne Walk: Carnacki, the Untold Stories which continues the adventures of occult investigator Carnacki the Ghost-Finder, originated by William Hope Hodgson.
The "electric pentacle" is a fictional electronic device invented by author William Hope Hodgson and used in several of his short stories about Carnacki the Ghost-Finder.
In an interview with Lumley, Robert M. Price suggests various possible models for Crow, including Miro Hetzel, Jack Vance's futuristic detective, Doctor Who, Mervyn Peake's Titus Groan, August Derleth's Dr. Laban Shrewsbury, William Hope Hodgson's Carnacki and Seabury Quinn's Jules de Grandin.