On July 4th, 2012, one of physics' most exhilarating results was announced: an entirely new kind of particle had been discovered at the Large Hadron Collider. The particle—a Higgs boson—is the key to verifying and understanding the Higgs mechanism that underlies elementary particle masses. Harvard University Professor Lisa Randall, one of the world's most cited and influential theoretical physicists, and author of the bestselling Knocking on Heaven's Door and Warped Passages, deftly explains both this epochal discovery and it's startlingly beautiful implications. . .