Ask anyone familiar with David Mitchell's 2004 novel Cloud Atlas about whether it can be turned into a film and they will tell you that it's "unadaptable." Not because of the story, which is actually quite linear, but because of the structure. Consisting of six separate yet subtly interconnected stories that span hundreds of years, from a nineteenth-century merchant ship to a far-flung futuristic wasteland, Mitchell cuts all but one story in half, then shifts from one story to the next as each reaches a cliffhanger, then returns to tell the second half of each story as the novel moves towards its end. (Or, to put it into numerical terms, the stories progress thusly: 1-2-3-4-5-6-5-4-3-2-1.) It's a Russian doll of a novel in which each story contains the next, and as such would be dramatically frustrating in any medium.