Body-snatching has never been so heartwarming. The Humans is a funny, compulsively readable novel about alien abduction, mathematics, and that most interesting subject of all: ourselves. Combine Douglas Adams’s irreverent take on life, the universe, and everything with a genuinely moving love story, and you have some idea of the humor, originality, and poignancy of Matt Haig’s latest novel.

Our hero, Professor Andrew Martin, is dead before the book even begins. As it turns out, though, he wasn’t a very nice man--as the alien imposter who now occupies his body discovers. Sent to Earth to destroy evidence that Andrew had solved a major mathematical problem, the alien soon finds himself learning more about the professor, his family, and “the humans” than he ever expected. When he begins to fall for his own wife and son--who have no idea he’s not the real Andrew--the alien must choose between completing his mission and returning home or finding a new home right here on Earth.

A prime number is a lonely thing. It can be divided only by itself or by one; it never truly fits with another. Alice and Mattia are both “primes”—misfits who seem destined to be alone. Haunted by childhood tragedies that mark their lives, they find themselves unable to reach out to anyone else. When the two meet as teenagers, they recognize in each other a kindred, damaged spirit.

As they grow into adulthood their destinies seem irrevocably intertwined. But when Mattia accepts a research position that takes him thousands of miles away, the two are forced to separate with many things left unsaid. A chance encounter will reunite them and force a lifetime of concealed emotion to the surface, but the question remains: Can two prime numbers ever find a way to be together? The Solitude of Prime Numbers is a stunning meditation on loneliness, love, and the weight of childhood experience.