Have you heard of _Twilight_? Are you acquainted with the undead? How about werewolves? Vampires? Angsty adolescent superheroes? This is our culture right now, and it's no exaggeration to say that it all began with one man: Joss Whedon, the creator of _Buffy the Vampire Slayer_ and arguably the most inventive pop storyteller of his generation. So how come Whedon never became as famous as so much of the derivative trash he inspired? Better question: Now that his summer blockbuster, _The Avengers_, is about to arrive, isn't this the part of the story where the overlooked hero rises to meet his big moment?