Linus Pauling was the most important chemist, and arguably the most important American scientist, of the 20th century. From his description of the chemical bond to his discovery of the cause of sickle-cell anemia and his groundbreaking work with vitamin C, his work leaped over the boundaries of disciplines, including chemistry, physics, biology, immunology, nuclear physics, and more. Now in this exciting new biography, acclaimed science writer Tom Hager brings Pauling's wide range of scientific accomplishments vividly to life while also shedding light on Pauling's activities outside the scientific realm. He shows how Pauling used his scientific fame to help advance political causes, particularly the battle against the spread of nuclear weapons during the 1950s. Despite the trouble his political activism caused him, he remained unmoved in his dedication to making the world a safer place. His perseverance was rewarded with a Nobel Peace Prize in 1963, making him the only person in history to win two unshared Nobels. In Linus Pauling, we read about a true a scientific giant: imaginative, bold, and unafraid of anyone and anything.