A theoretical physicist returns by train from a conference, his eyes fixed on a paper on quantum cosmology. Suddenly, a little girl's voice interrupts his musings. "What are you reading?" "It's the story of the universe." "If it tells the whole story of the universe, does it say anything about me?" Starting from this question, this book explores our current understanding of the Big Bang, the primordial event that gave rise to the special mixture of space, time, and matter that we call the universe. It is a journey through cosmic history, pushing the limits of human knowledge, winding its way through general relativity, curved spaces, quantum mechanics and the multiverse. Giudice succeeds in uniting science and the history of thought, tracing the debate that animated the physics community, when faced with the hypothesis and then the confirmation of the Big Bang. This book recounts the great discoveries in cosmology and leads us to the frontiers of current scientific research. It is a fascinating and thought-provoking parable that addresses complex concepts with the fluidity of storytelling and allows us to better understand the universe around us.