Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Imaginative, sometimes comic

Michael is a young doctoral student in England whose thesis centers on the early life of Adolf Hitler. He encounters a physicist who harbors a deep hatred of Hitler (as well as a deep secret), and the two hatch a plot to make so Hitler was never born. The two change history, but the world doesn't turn out how they intended. Michael struggles in this new, disturbing world to find the physicist and to right the wrong, and along the way he finds love with another man. But will this love survive when they try to set the world right? Sometimes fun, always intelligent, this novel can be called a sci-fi comedy, or just a highly imaginative book. Any which way, though, Fry's book is a marvelous read about history and our views on it.