The New York financier J.P. Morgan was not only a canny investor and a passionate art collector—he was also exceedingly superstitious. Interested in the occult, a believer in astrology, and an obsessive solitaire player, his interests dovetailed in the 1911 acquisition of dozens of cards associated with a legendary 15th-century tarot deck, created for Milan’s ducal Visconti-Sforza family by the northern Italian artist Bonifacio Bembo.