Harry Houdini's expose of the fraudulent spiritualist, spirit photography, spirit slate writing, ectoplasm, clairvoyance, and other quakery and cons perpetrated on desperate believers. Specific spiritualists covered in the book include Dr. Slade, the Davenport Brothers, Anne O'Delia Diss Debar, the Fox Sisters, Daniel Dunglas Home, Eusapia Palladino, and other con artists of their ilk. The whole nation was excited by Houdini's campaign against fakers. He traveled across the country, offering money for spirit activities he would be unable to duplicate by his use of skilled illusions. It was a heyday not only for Houdini, but for the spiritualists themselves -- and there was an equally famous protagonist who thought the spirits could indeed be contacted, Sir Arthur Conan Doyle. A photo at the start of the book records a meeting between Houdini and Doyle, who is given his own chapter in the book. There's also a full section on Daniel Dunglas Home, the English engineer of spectacular paranormal effects. Houdini saves his sharpest arguments for spiritualists who were giving their (usually paying) clients a vision of the hereafter, and shares the methods used to practice "fake" and sensational spiritualism. Houdini was nothing if not unrelenting. As a taste of things to come, he ends his introduction with the words: "Up to the present time everything that I have investigated has been the result of deluded brains," though Houdini attests to his own open mind on the topic of the afterlife and recounts his personal attempts to communicate with the dead.