I owe a debt to works by James Randi (An Encyclopedia of Claims, Frauds, and Hoaxes of the Occult and Supernatural, The Psychic Healers, and Flim-Flam!) and M. Lamar Keene (The Psychic Mafia). These acted as invaluable guidebooks on what to look for on my visits to Spiritualist churches and psychic mediums.
Thanks to the usual crew for their editorial help on the manuscript: my wife Mary; my editor David Hartwell; his assistant Moshe Feder; Elizabeth Monteleone; Steven Spruill; and my agent Albert Zuckerman. And thanks to Blake Dollens, typo master, for his help with this edition.