Black holes are an extraordinary construct, proposed by theorists and embraced by the popular imagination. They represent a mysterious, unexplored frontier where time and space behave in bizarre ways. In essence, black holes are an idea written, spoken, and thought about, but a fundamental question has always remained: Do black holes exist? Astrophysicists Mitchell Begelman and Martin Rees answer this question with a resounding yes. Central participants in the quest to understand black holes, they describe the great technological advances that have allowed scientists to gather compelling evidence that black holes are a real and ubiquitous phenomenon. These points where gravity is infinitely strong, "swallowing" everything in its vicinity, could number in the millions in every galaxy, as the remnants of ordinary stars several times more massive than the Sun. More remarkably, discoveries made early in 1995 supply conclusive evidence that giant black holes, perhaps weighing as much as billions of suns, are lurking at the very center of most galaxies. Gravity's Fatal Attraction: Black Holes in the Universe tracks the observations and accidents through which scientists discovered black holes and the related phenomena they power, such as quasars and dazzling jets a million light-years long. Scientists are just beginning to understand the exotic ways these invisible objects manifest themselves, and how they relate to other structures in the cosmos. Yet, new questions continue to arise: Could microscopic holes exist, the size of an atomic nucleus but the weight of a mountain? As the Universe evolves, could it be the ultimate fate of all matter to be "swallowed" by black holes? As Begelman and Rees point out, the cosmic "fireworks" scientists are investigating may prove most valuable as stepping-stones to even more profound knowledge. The quest to find black holes and related structures, and to understand the mysterious work of gravity within them, could ultimately confirm or refute our theories describing the physical laws of the Universe, and even help us understand its origins and final fate.