Human ancestors entered the underground world millions of years ago, yet only recently have scientists realized the extent that our early relatives stretched their activities into the dark spaces beneath us. Starting from his own work in the Rising Star cave system of South Africa, Dr. John Hawks follows a track connecting extinct human relatives like Homo naledi with Neanderthals and early people in the caves of Africa, Europe, and Asia. The talk explores the long connections of ritual and art with underground space, through a consideration of the psychological and sensory effects of dark.