Imagine a future where we are not alone - where our universe is just one of countless parallel worlds, some strangely familiar, some almost unimaginable. And that, when planet earth finally runs down to a cold, dark wasteland, we will be able to escape into these new worlds and start again. Michio Kaku's thrilling guide to the galaxy shows us how it could happen sooner than we think - and the future for intelligent life is one of endless possibilities.