Comic book universes are often cited as mythologies of the modern era. Superman, Spiderman, Wonder Woman, The Hulk—these are the new gods, the Zeus, Poseidon, Apollo, and Athena of our day. But the strongest similarities between Greek myth and American comics have less to do with characters (or their supernatural powers) than with an ever-growing, interweaving tapestry of story.

There would be very little force in Aeschylus’ Oresteia—the story of Orestes’ revenge on his mother Clytemnestra, murderer of her husband Agamemnon, Orestes’ father—if the story of Agamemnon had not already been explored in Homer’s Iliad (in which he commands the Greek forces at Troy). The dark family history of Agamemnon is assumed in Aeschylus’ tragedy, all its symbolisms of rape, murder, and incest augment the Oresteia’s expansion on it.

Frank Miller’s The Dark Knight Returns

The same idea goes for Frank Miller’s The Dark Knight Returns, the noirsh tale of a geriatric Batman coming out of retirement (arguably the best in the canon). Miller drew on what was 48 years of Batman stories, from Bob Kane to Dennis O’Neil, from 60s camp to 70s brooding. All of it informs The Dark Knight Returns’ introspective depiction of a beast at war with the man who embodies it.

Both stories draw depth from the narrative universes to which they belong, more depth than either could achieve alone. And tales that came after used these in the same way. This is a unique feature of mythology: every story lends every other a special weight. Shared characters develop a life’s worth of pain, triumph, anxiety, affection. And as the tapestry grows larger and tighter, individual threads become more sensitive to effects on others and the whole. It’s why we keep returning to Greek myth. It’s why we love comic books.

When it comes to film, Marvel Comics understands this. With Iron Man, The Incredible Hulk, Captain America: The First Avenger, and Thor, Marvel rolled out an incredible (and incredibly successful) campaign to entwine its heroes’ worlds. The first “phase,” as they called it, featured origin stories, a necessary hurdle—average filmgoers weren’t familiar enough with Thor or Iron Man. Then, with groundwork laid and a number of hints that something bigger was on the way, Marvel Studios delivered The Avengers, the first shared-universe comic film.

It’s hard to overstate the impact. Under the guidance of director Joss Whedon, The Avengers came off beautifully. But the real payoff was next. With Iron Man 3, Marvel released a film in which the facts of a shared universe fed back and added special weight to Tony Stark’s new life and story. It’s something more than a sequel. It’s something that’s never been done before in film.

Compared to this, DC Comics’ heroes are hopelessly alone. They exist awkwardly on separate film islands. Superman doesn’t know Batman. Green Lantern doesn’t know Wonder Woman or Martian Manhunter or Aquaman. Nobody knows The Flash. Christopher Nolan did a superb job with Batman Begins and The Dark Knight, but his Gotham City has no sister in Metropolis. Every hero is the first of his kind.

This doesn’t necessarily make for dull movies, but it keeps DC Comics from reaching a potential Marvel has already begun to attain—the true mythic potential of comic book films. For fuck’s sake, what’s the fun of DC Comics without the DC Universe?

Hopefully the announcement at the San Diego Comic Con—that the Man of Steel sequel will feature Batman—means that DC has finally started to get its act together. There are even rumors that a Justice League movie (the superior analog to the Avengers, in my opinion) is in the cards for 2017. Fingers and toes crossed.

Who knows what phase Marvel will be in by then? The stories can only get deeper and more complex. It’s a big production to fold directors, actors, and writers into a shared universe, but it’s worth all that trouble if the product is a whole new class of cinema.