One of the world's most celebrated cosmologists presents her breakthrough explanation of our origins in the multiverse. In recent years, Laura Mersini-Houghton's ground-breaking theory, spectacularly vindicated with observational evidence, has turned the multiverse from philosophical speculation to one of the most compelling and credible explanations of our universe's origins. In Before the Big Bang, she interweaves the story of how she arrived at this theory with her journey from communist Albania, where she was born and brought up, to the West, showing how her unconventional path helped her to challenge orthodoxies and become one of the most courageous thinkers on the world stage of theoretical physics.