This book tells the story of a physicist's sixty years of experimental research into subatomic particles, eventually showing that the quarks that are forever trapped inside protons are smaller than a trillionth trillionth the size of the smallest atom, hydrogen. The author describes how he and his colleagues made many different types of particle detector, explaining how these enable us to "see" these tiniest constituents of matter, and how they were used to search for new fundamental particles. He tells the story of his search for the fourth quark, charm, and the weak force carriers W and Z, and how others found them, but then he participated in the discovery of the most massive top quark at Fermilab and the Higgs boson at CERN. His descriptions of the physics are accessible to a general reader, alongside personal stories including some encounters with great physicists.