This highly readable book uncovers the mysteries of the physics of elementary particles for a broad audience. From the familiar notions of atoms and molecules to the complex ideas of the grand unification of all the basic forces, this book allows the interested lay public to appreciate the fascinating building blocks of matter that make up our universe. Beginning with a description of the quantum nature of atoms and particles, readers are introduced to the elementary constituents of atomic nuclei: quarks. The book goes on to consider all of the important ideas in particle physics: quantum electrodynamics and quantum chromodynamics, the theory of strong interactions, the gauge theories of the weak and electromagnetic interactions, as well as the problem of mass generation. To conclude the book, the ideas of grand unification are described, and finally, some applications to astrophysics are discussed. Your guide to this exciting world is an author who, together with the originator of the idea of quarks, Murray Gell-Mann, has played an important role in the development of the theory of quantum chromodynamics and the concept of grand unification.