“Must be some kind of…hot tub time machine.”
Most prequels are not necessary, because a lot of stories are a lot better if you know a lot less about the characters and the world. As Patton Oswalt said, “I don’t want to know where the stuff I love comes from. I want to love the stuff that I love.”
Enter X-Men: Days of Future Past, a cross between a sequel and a prequel that justifies its existence by being the most consistently entertaining blockbuster released so far this summer. It succeeds in bringing back the feel of the original X-Men movies while expanding the universe greatly. I have always been a big fan of X-Men, partly because its built-in allegory works so well. It is one of the darkest of all superhero stories yet as a movie franchise, it does not try too hard to be gritty.