Enough digital ink has been spilled over the awfulness of Zack Snyder’s Batman v Superman: Dawn of Justice, but allow me to add a drop of a different color. While most critics have focused on the lack of character motivation, the skimpy writing, the overwhelmingly complicated plot, the poor direction, the bland score, too much time devoted to setting up future features, and the overwhelming sense of gloom and cynicism, few have focused on the source material that led to this cinematic disaster and how this work became so poorly translated.

Batman v Superman: Dawn of Justice was deeply inspired by a pivotal comic from 1986, the year of my birth. Written and drawn by Frank Miller with inks by Klaus Janson, The Dark Knight Returns redefined modern superhero comics. Showcasing a grounded, realistic, deeply serious approach to Batman and Superman, The Dark Knight Returns helped inaugurate the grim ‘n gritty comics of the 1980s, a storytelling approach where—to invoke Heath Ledger’s Joker for a moment—heroes were brought down to our level.

The Dark Knight Returns is packed with manic energy but also tremendously self-serious, a formula that launched a thousand imitators and scarred superhero comics for decades. Calling the book widely popular is a mild form of praise. Miller had already cut his teeth on a gritty Daredevil run for Marvel, but The Dark Knight Returns cemented his status in the comic creator pantheon.

The most obvious connection between The Dark Knight Returns and Batman v Superman is the centerpiece knockdown fight between Batman and Superman. That’s the whole premise to cartload audiences into the local megaplex. People have to see that fight. Sadly, that fight lasts minutes in a film bulging at the running-time seams. More importantly, that fight forgets something important: these characters need a logical reason to fight. Lex Luthor’s trick is so obvious, it’s insulting to both characters’ intelligence. It’s as if the film is saying they fight simply because that’s what superheroes do, not because of larger reasons of philosophy or motivation.

So, the ultimate failing of Batman v Superman is that Zack Snyder doesn’t understand what makes DC Comics great. The Dark Knight Returns partially falls into the same trap: though Miller handles the moral and philosophical differences between the two tentpole characters better than Snyder, he still shows a distinct lack of care for most characters. There’s no equivocation. Miller is firmly a Batman partisan and exhibits a regrettable tendency common in comics: to build one character up while nerfing another into an inept dummy stripped of their humanity.

One only has to look at Miller’s follow-up, the disastrous The Dark Knight Strikes Again to see the limitations of Miller’s understanding. Or look at a repeated sequence in Batman v Superman where Batman shoots a kidnapper in the face with a machine gun.

Using The Dark Knight Returns as a model for superhero movies is a dead end. Man of Steel took the grim ‘n gritty approach embodied by Miller to nightmarish levels. Thousands died. Superman snapped Zod’s neck because he couldn’t imagine doing anything else. The key irony is that this ur-ubermensch no longer embodies the meaning of the word in Snyder’s telling. Uber, after all, translates to ‘over’. Shouldn’t Superman be above this kind of violence, finding new and different ways to transcend boundaries and all-too-human choices?

But here’s the sad part: there’s an infinitely better Batman/Superman story that Zack Snyder could have adapted, one that audiences both need and deserve. A decade after Miller’s The Dark Knight Returns, writer Mark Waid and artist Alex Ross authored a four-part prestige series called Kingdom Come that understood something most DC films (and many DC comic series) don’t: realistic and mature stories don’t have to be ultra-violent and cynical.

Featuring a world on the brink of chaos, where superpowered characters have alienated the average citizen, Kingdom Come is set in the near-future where the old breed of heroes have receded from public service as their more violent progeny battle simply for the pleasures of battle. Millions die in the crossfire as the lines between hero and villain blur. After Kansas and much of the Midwest is irradiated, Superman—self-exiled after the death of the Daily Planet staff by the Joker—returns to set things right. He encounters allies and foes, including an increasingly militant Wonder Woman and a paranoid, aging Batman keeping order in Gotham through blunt, authoritarian ways, using power armor to bash criminals.

Sound familiar?

The parallels between Kingdom Come and Batman v Superman: Dawn of Justice are staggering. Batman and Superman are on opposite sides of a debate. Wonder Woman’s a wildcard. The public distrusts superheroes. Mass destruction undermines trust. Lex Luthor manipulates both sides to his advantage. There’s even a near-unstoppable villain that Superman must confront during the narrative’s climax.

However, Kingdom Come gets these elements right because the characters’ motivations are grounded in their idiosyncratic perspectives. Snyder doesn’t give a shit about those. He cares about cool-looking shots.

One of the more egregious aspects of Batman v Superman is how easily the World’s Greatest Detective is manipulated by Lex Luthor: a few pieces of hate mail push Batman into attempted murder. Kindly Superman is portrayed as a dunce who could have prevented the entire battle with a few simple words. The defining traits of these characters—Batman’s intellect and Superman’s humanism—are ignored in favor of spectacle.

Thus Batman v Superman is a backwards film that abolishes the history of these characters. Kingdom Come, on the other hand, relishes this history and makes for a far more satisfying experience, as the differences between Batman and Superman come from their shared experiences, and are expressed in moral and philosophical disagreements, not illogical misunderstandings.

A key example in Kingdom Come is when Superman confronts Batman in his cave right before a climactic battle. Throughout the narrative, Batman has worked against Superman’s revived Justice League with a group of Outsiders, second- and third-generation heroes without superpowers, suspicious of the gods above. Instead of throwing a punch or getting wacked with a porcelain sink, Superman articulates their differences better than any fight could settle:

“The deliberate taking of human—even super-human—life goes against every belief I have—and that you have. That’s the one thing we’ve always had in common. It’s what made us what we are. More than anyone in the world, when you scratch everything else away from Batman, you’re left with someone who doesn’t want to see anybody die. We can still intercede. Gather your forces. Together, we can be the World’s Finest Team.”

And team up they do, saving the day, though at great personal cost.

This scene shows a deep appreciation of these characters’ differences without reducing them to CGI toys. Superman fights for truth and justice. Maybe that’s hokey to a contemporary Warner Bros. executive, but no one is asking for a remake of Richard Donner’s Superman from 1978. That belongs to a specific era. Kingdom Come proves that these themes and characters can be represented with maturity without compromising the save-the-day ethos of superheroes. Nihilistic violence should not be equated with a grown-up superhero story.

Kingdom Come is the confrontation between Batman and Superman we deserve. Though The Dark Knight Returns kicked off this conflict, it’s a far less satisfying project in comparison. The most interesting superhero fights aren’t products of their fists, but clashes of their hearts and minds.