After their adventures in India, the Doctor and Clara return to her present - but danger is slipping through the cracks between universes, and London has no defence against the Fractures! Will the Doctor risk all of reality to reunite a family - or sacrifice a good man to keep the multiverse intact? Then, the Doctor gambles with his life in 1960s Las Vegas, as he and Clara must team up with gangsters in order to defeat an intergalactic crime syndicate, but is this one too many spins on the Doctor's roulette wheel?