Pamela Colman Smith, newly arrived from New York to her birthplace of London, is received as an oddball in Victorian society. Her second sight helps her in her new job: illustrating tarot cards for the Golden Dawn, a newly formed occult group. But when Pamela refuses to share her creations with Aleister Crowley, a controversial magician, he issues a threat: give up the cards' power, or he'll harm her muses.

In the midst of this battle, two of Pamela's idols, the actors Henry Irving and William Terriss, take her under their wing. Henry, who tutors her as the leader of the Lyceum Theatre, becomes the muse for her Magician card. William Terriss, teaching her by examples of instinct and courage, becomes the muse for her Fool card. As Pamela begins to create the tarot deck, she is almost overwhelmed by the race to possess the magical power of her cards. In order to defeat Aleister, Henry, and William will have to transform into living incarnations of the Magician and the Fool—and Pamela will have to learn how to conjure her own magic.