Ann Stilwell arrives in New York City, hoping to spend her summer working at the Metropolitan Museum of Art. Instead, she is assigned to The Cloisters, a gothic museum and garden renowned for its collection of medieval and Renaissance art. There she is drawn into a small circle of charismatic but enigmatic researchers, each with their own secrets and desires, including the museum's curator, Patrick Roland, who is convinced that the history of Tarot holds the key to unlocking contemporary fortune telling. Relieved to have left her troubled past behind and eager for the approval of her new colleagues, Ann is only too happy to indulge some of Patrick's more outlandish theories. But when Ann discovers a mysterious, once-thought lost deck of 15th-century Italian tarot cards she suddenly finds herself at the centre of a dangerous game of power, toxic friendship and ambition.