Professor Andrew Martin, a mathematician at Cambridge University, has just proved the Riemann hypothesis, an action that represents a huge breakthrough with dramatic consequences for the improvement of human science and technology. Unfortunately, his discovery has come to the attention of an alien race that, believing all humans are motivated by violence and greed, will do anything to prevent it from going public. Therefore, one of the aliens is sent to Earth to invade the professor’s body, destroy the proof of the Riemann hypothesis, and kill anyone who might know about the discovery — including the professor’s wife and troubled teenage son. At first, the alien is eager to complete his mission; but the more time he spends on Earth, the more he comes to understand and even love the humans around him.
I went into this book knowing very little about it, and I was pleasantly surprised by how much I enjoyed it! Matt Haig has a light, playful style but doesn’t shy away from more serious moments, as when the alien narrator begins to feel the tension between his growing empathy with the humans and his own cultural values. I liked that the book is a sort of philosophical thought experiment, exploring how the human race might look to an intelligent but emotionally detached outsider, and ultimately considering the question of what it means to be human. Oddly, I found the human culture on display in this book to be a bit off-putting . . . for example, the fact that Andrew Martin’s son is named Gulliver rubbed me the wrong way. But overall, this is a fun read with a good mixture of levity and thoughtfulness.