Rare book dealer Lily Albrecht has just been given a tip-off about The Book of the Most Precious Substance, a 17th century manual rumoured to be the most powerful occult book ever written, if it really exists at all. With some of the wealthiest people in the world willing to pay Lily a fortune to track it down, she embarks on a journey from New York to New Orleans to Munich to Paris. If she finds it, Lily stands to gain more than just money. This could erase the greatest tragedy of her life. But will Lily's quest help her find some answers, or will she lose everything in search of a ghost? 'Gran's writing, like the grimoire, is palpably seductive. The search for pleasure and magic is an aphrodisiac, one that pulses on the page.' - The New York Times