a deal with the devil

'Easy prey': How a massive psychic fraud gained its power

CNN journalists Blake Ellis and Melanie Hicken have spent years investigating one of the largest consumer frauds in history -- a case that has stumped global investigators for decades. The scheme, which duped victims out of millions of dollars with letters claiming to be from a famous French psychic named Maria Duval, is the subject of the reporters' new true crime book, "A Deal with the Devil." The following excerpt has been edited for brevity.