Laura Mersini-Houghton is on the trail of, quite literally, the biggest secret code going. Her analysis of the faint microwave radiation that permeates the sky, called the Cosmic Microwave Background, reaches a startling conclusion: She believes that it (along with recent particle physics data) provides definitive, empirical evidence that our universe is just one of many. If proven to be true, this would change our understanding of what nature is and where its laws come from. When we caught up with Mersini-Houghton in Ann Arbor, Michigan, we found someone who carried the weight of her work lightly. Quick to smile and full of anecdotes, Mersini-Houghton took us from the farthest reaches of the multiverse to her family home in communist Albania.