Zafon's (The Watcher in the Shadows, 2013) haunting tale transports readers to 1979 Barcelona where 15-year-old Oscar Drai lives a dreary boarding school life. Instead of studying, he explores the city, and one day ends up in the garden of an old mansion. Here he meets Marina who lives a quiet life with her father. She leads Oscar to a cemetery where they witness a woman dressed in black lay a single rose atop a gravestone etched with a black butterfly. When they decide to follow her, the two discover dark secrets and sinister forces that put their lives in jeopardy.