Dara and the team probe the miniscule and the enormous to reveal why size matters and how discoveries at either end of the scale are changing the way we view the universe. Professor Mark Miodownik discovers an astonishingly effective lo-tech weapon in the battle against nefarious hospital superbugs. Science journalist Alok Jha visits a premature baby unit in Canada to see how Big Data can save tiny lives. Dr Helen Czerski goes a mile underground in South Dakota to join the hunt for our missing universe and the team visits the New York Stock Exchange to find out how much a millisecond is worth in hard cash. In the studio, Dara investigates the explosive effects of size and Mark swallows a miniature camera to reveal his internal organs.