Scientists widely accept the existence of quarks, the fundamental particles that make up protons and neutrons. But information about them is still elusive, since their interaction is so strong that their direct detection is impossible and exploring their properties indirectly often requires extremely expensive particle colliders and collaborations between thousands of researchers. So, quarks remain conceptually foreign and strange like the Cheshire cat in “Alice’s Adventures in Wonderland,” whose grin is detectable—but not its body.