"Game of Shadows" is a book by Mark Sullivan that delves into the world of Sherlock Holmes and Dr. John Watson. It explores the intricate relationship between the famous detective and his nemesis, Professor Moriarty, as they navigate a web of crime and deception in Victorian London. The narrative combines historical events with fictional elements, providing a thrilling backdrop for the characters' adventures. The story highlights themes of loyalty, betrayal, and the moral complexities of justice, making it a captivating read for fans of mystery and detective fiction.