The multitude of movies that feature a post-apocalyptic setting seem to have grown with a geometric progression over the past couple of decades. Start with the end of the world, then develop the plot from that point forward.

One of the classic "end of the world" novels is Stephen King's The Stand. But even King himself mentioned that the germ of the idea had its roots in story lines that preceded him. George Romero's Night of the Living Dead, for example, has a similar premise that concerns a small band of survivors taking on an empty world (and monsters.) And George Romero himself said that in composing Living Dead, he basically "ripped off" Richard Matheson's I Am Legend. And as far as literary precedents go, you can probably go back even further than that.

This type of storyline doesn't come as a huge surprise. If nothing else, it probably has its roots in the middle ages and survivors who passed down stories of surviving the black plague. But there's something lacking in Hollywood when every new idea has to fit into a category that's already been established. ("It's 28 Days Later, but with werewolves and it take place in Japan.") That's the beauty of the movies that the Cohen brothers produce: when people ask others to describe the movie, the most common thing you hear is something like, "You know...it's a Cohen brothers movie." You know you're dealing with a masterpiece when the artists themselves have become the primary descriptor.

It's pretty easy to begin where someone else left off. It takes real insight and guts to start at zero.