Let us journey, with beloved physicist Carlo Rovelli, into the heart of a black hole. We slip beyond its boundary, the horizon, and we tumble - on and on - down this crack in the universe. As we plunge, we see geometry fold, see time and space pull and stretch. The remains of a star, ever more dense keep falling, deep and further far. And then - the bottom. Where space and time dissolve, and a white hole is born ... With lightness and magic, here Rovelli traces the ongoing adventure of his own cutting-edge research, the uncertainty and the hesitations of traveling where we have not been before as we explore hypotheses and new worlds. Guiding us into the horizon, he invites us to experience the fever and the disquiet of science -- and the strange and startling life of a white hole.