Detailed Instructions: You will be given a trivia clue, and the category it belongs to. You should answer with the best answer that belongs in the category and is described by the clue. For simplicity, answers should be in all lower cased letters.
Q: Category: HISTORIC MEDIUMS 
Clue: In the '20s the alleged spirit powers of Margery caused a rift between these 2 men, a magician & a writer
A:
harry houdini & sir arthur conan doyle