NY Times bestselling author Sam Kean takes us on a journey to tell the epic story of the air we breathe. With every breath, you inhale the history of the world. Of the sextillions of molecules entering or leaving your lungs at this moment, some might bear traces of Cleopatra's perfumes, German mustard gas, particles exhaled by dinosaurs, even remnants of stardust from the universe's creation. Guardian Science Book of the Year 2017.