Romilly Kemp and her eccentric father have happy but sheltered lives in a ramshackle mansion in the English countryside. To help make ends meet, he creates an illustrated book with Romilly—striking girl with red hair and a mole on her cheek—as the heroine with her cat, Monty. The book becomes an instant success and their estate is overrun with tourists and adventure seekers after rumors spread that hidden within its pages is an elaborate treasure hunt. As Romilly gets older and her father writes more books, he starts disappearing within himself. She returns to his illustrations, looking for a way to connect with her ailing father, and finds a series of clues he’s left just for her. But this treasure hunt doesn’t lead her to gold or precious stones, but something worth far more—a shocking secret that is crucial to understanding her family.