A gripping erotic thriller about the lengths to which we are willing to go to get what we need... and what we want. After a tragedy that upended her entire life, former writer Lily Albrecht resigned herself to the dull, colorless existence of a rare dealer books. Until I received an offer to find a book that could fix everything... The Book of the Priceless Substance is a manual on sex magic from the 17th century, promising unlimited power and unsurpassed sexual pleasure. According to rumors, this is the most powerful occult book in the world, and some of the rich are willing to pay a fortune to get their hands on it... Unless it's just an old legend. But will Lily be able to fulfill her own wishes? Or will she lose everything in pursuit of a mirage? “Sara Gran’s style, like the wanted grimoire, is palpably seductive. The search for pleasure and magic is an aphrodisiac that pulsates through the pages.” – Daniel Trussoni, bestselling author and New York Times literary columnist “A sensational occult thriller. Graen's writing is incredibly seductive - like Lily Albrecht, readers have no choice but to follow the book to its ominous conclusion." – New York Times “Sarah Gran's book is a mixture of shopping mystery, erotica and a pinch of existential horror. And it’s all great.” – Paul Tremblay, bestselling author of The Cabin at the End of the World “Extravagant, sexy and irresistible. I like it". – Lauren Beukes