A new analysis of collisions conducted at different energies at the Relativistic Heavy Ion Collider (RHIC) shows tantalizing signs of a critical point — a change in the way that quarks and gluons, the building blocks of protons and neutrons, transform from one phase to another. The findings will help physicists map out details of these nuclear phase changes to better understand the evolution of the universe and the conditions in the cores of neutron stars.