If black holes collide in outer space and no one can see it, does it make a sound? A black hole collision is an event more powerful than any since the origin of the universe. But when black holes collide, they will do so unilluminated – emanating only gravitational waves. The only evidence would be the sound of spacetime ringing. Levin shares the obsessions, the aspirations, and the trials of the scientists who embarked on an arduous, fifty-year endeavor to capture these elusive waves and record the soundtrack of the universe.