Unsolvable premises

Awhile ago I was thinking that one way to give a film interest is to provide it with an unsolvable premise. A good example is Casablanca which asks the question, "how can a woman having an affair be heroic?" Another example is Unbreakable which asks, "how can you make a comic book movie that doesn't end with a climactic battle?" I do like the Unbreakable premise. How would you do it? Unsolvable premises could also be a matter of execution. I was watching bits of Spiderman 3 on Netflix instant a few days ago. The shot (that they used in the trailer) of Tobey McGuire sailing through the air grasping at the wedding ring is a beautiful image. How could you create a superhero film with images like that but cheap and without visual effects?