What came before the Big Bang, and what exists outside of the universe it created? Until recently, scientists could only guess at what lay past the edge of space-time. However, as pioneering theoretical physicist Laura Mersini-Houghton explains, new scientific tools are now giving us the ability to peer beyond the limits of our universe and to test our theories about what is out there. Mersini-Houghton’s groundbreaking research suggests that we sit in a quantum landscape whose peaks and valleys hide a multitude of other universes, and even hold the secret to the origins of existence itself. Recent evidence has revealed the signatures of such sibling universes in our own night sky, confirming Mersini-Houghton’s theoretical work and offering humbling evidence that our universe is just one member of an unending cosmic family.