How did Houdini take on the Boston medium 'Margery'?

In 1924 the magazine Scientific American offered a prize to any medium who could demonstrate telekinetic ability under scientific controls. One candidate was Mina Crandon, the wife of a wealthy Boston surgeon, who performed as 'Margery' and claimed to channel her dead brother, Walter Stinson. With a doctor as husband, she was well prepared for the challenge, and her charm and lack of interest in personal monetary reward made her seem honest to the public. Sir Arthur Conan Doyle, the author of Sherlock Holmes, touted her abilities.

The prize committee had a Harvard psychology professor, two psychical researchers, a Technicolor pioneer and Harry Houdini. Houdini turned his energies in the 1920s toward debunking mediums in order to show how they were taking advantage of the bereaved, and his training in magic allowed him to expose frauds who had successfully fooled many scientists and academics. After two sittings, Houdini said Margery had escaped control and stretched her foot to ring a bell in the séance room.

Houdini then asked her to wear a large cabinet-box that prevented her from using her legs, leaving only her head and hands sticking out. The bell rang, but when the lights came on the lid of the cabinet-box had been forced open, and Houdini claimed she had rung the bell herself. Under a stricter control, no paranormal phenomena were observed, and Margery did not win the prize.

That was not the end of the argument. Doyle refused to credit any of Houdini's exposés and came to believe that Houdini himself was a powerful spiritualist medium, using those abilities to block the powers of the mediums he supposedly debunked. Houdini turned his efforts into his stage act, reproducing her effects for audiences.