With the use of stunning three-dimensional cosmic simulations captured with revolutionary high-definition technology, NOVA presents the first attempt to explore the riddle of "dark energy"- the mysterious repulsive force that some scientists believe counteracts gravity. Runaway Universe presents the dramatic quest to unlock secrets of the stars as two rival teams search for exploding stars, map gigantic cosmic patterns of galaxies, and grapple with the ultimate question: what is the fate of the universe?