A sample of the ROMULUS25 simulation at redshift z = 0.4. The three slices of the simulation are focused on the same central group of galaxies (about 10 times as massive as the Milky Way), and shows the distribution of dark matter (left), the distribution of stars color-coded by composition (center; red are metal poor, blue are metal rich), and the distribution of stars color-coded by age (right; red are old, blue are young). White dots mark black holes.