On the occasion of The Dark Knight’s 10th anniversary, Polygon is spending the week investigating the comic-book blockbuster’s legacy . Why so serious? Because Christopher Nolan’s Bat-sequel gave us lots to talk about. This is the retrospective you deserve and the one you need right now.

In 2008, Scott Snyder saw The Dark Knight like every other Batman fan on the planet. In 2011, DC Comics would task him with first new era of Batman to be crafted in the wake Christopher Nolan’s blockbuster (not to mention Grant Morrison’s character-defining run). The run was one of few unequivocal success stories of the New 52 reboot, and Snyder is in the history books as one of “The Best at Batman.”

Snyder’s grip on what makes Batman Batman put him in the position of de facto architect of the Gotham setting even after his run was concluded. His and Capullo’s Death of the Family is among the greatest Joker stories ever put to page. If anyone can break the character down to his core, it’s Snyder.

Snyder has his own favorites; he puts Mark Hamill’s take on the character on a pedestal and says Batman Beyond: Return of the Joker is one of the “four or five” greatest Joker stories ever told. Heath Ledger’s joker in The Dark Knight has a place in his personal history, too. Here, as told to Polygon’s Susana Polo, Scott Snyder reflects on the Joker, Batman, and what makes the rivalry of these nearly 80-year-old folk characters tick.

The Dark Knight is very much, to me, a movie about modern fears. The Joker is a new kind of villain at that moment who just says, “I don’t believe in any of it, I don’t believe that we’re going to make it through. And I think we should just burn it all down.” Batman is that figure who is constantly trying to put the city back together, with the city as a construct of order and as civilized life. So as much as Batman’s the outlaw, he is a figure of affirmation in that way, and the Joker is a figure of complete entropy, and I love that relationship there.

It’s fun to look back and see how many versions of the Joker have been. He has versions where he’s more crazy or he’s more comical. The key, I think, is that he always has to be the extension of your version of Batman’s worst fears, whatever those are.

When I wrote Death of the Family, my wife and I were pregnant with our second kid and, this time around, I was very afraid of being a bad father because my career was starting to take off. And with the way things were, it seemed scary to bring another kid into the world.

The Joker in that story comes to Batman and says, “I know that deep down you don’t really love this family that you’ve created and instead you wish you could go back and be young again. It’d be me and you,” and that “All this baggage ... It’s making you mortal. You’re bigger than that. The way I am. Together we’re more, we’re legends. So let me do what you want me to do and kill all of them, and provide them proof why you love me and you better than you love you and them.”

[My final arc on Batman], Endgame, was the opposite. In Endgame, the Joker says, “OK, now you’re past it, you missed the chance. And now I’m going to show you what you missed. You could have been immortal.”

Endgame to me is pure Joker. Those are the things that I’ve said in my darkest moments. The things that he voices to Bruce about, “You’re afraid that this is what your life amounts to, you’re afraid this is who you are. You’re afraid that all those things are so, and let me prove it to you and show you how I’ll outlast you. And how when you’re long dead, I’ll still be here.”

So, it’s one long argument about Joker saying to him, at first, “There’s nothing good about being human. There’s no meaning to it. So join me and be this.” When Batman doesn’t, Joker comes back and says, “Now it’s a tragedy. This is the part where you go down, the Bat King of Gotham. I turn on you and show you how all of it is just a sandcastle and none of it means anything.”

To me, that was their big story. And then once that was finished, I knew that, for the time being, I had smaller Joker stories to tell.

Batman is the fantasy. He has the worst thing happen to him that could happen to a kid: both his parents murdered in front of him. For no reason, really. Over nothing. Over some pearls. No big plot, no big conspiracy.

So there isn’t even a real purpose to it. There isn’t even a sense of, “Well, that makes sense because my father wronged somebody.” There isn’t a narrative that would make this logical. Instead it’s supposed to prove to a child, essentially, that there’s no design to the universe, no causal logic, and everything is meaningless and everything is cruel.

But instead, he turns that into fuel to get up and say, “I’m gonna make my life the pinnacle of meaning, like an engine of meaning, and instead make myself matter and make sure that what happened to me can’t happen again to another child.”

The Joker always has to be the opposite of your interpretation of Batman. Heath Ledger’s Joker represented the driving force of chaos, he was entropic and completely about the disillusion of order, disillusion of civilization and the ridiculousness of the belief that any of that could hold things together. And Batman in that movie seemed to be this force of order, this sense of no matter how bad things get, if we live by certain codes, certain ethical tenets, we can pull it back from the brink, and this kind of beacon.

The Joker says, “There is no causal chain of things that make sense except cruelty and evil and those things, and I can be anything I need to be to show you how that so.” And him not having an origin, in my opinion, is one more facet of that same sort of nimble, terrifyingly liquid nature. He can be anything he needs to be to prove his point. You can’t solve the mystery of him. Batman is the greatest detective in the world. The one origin he can’t figure out is the Joker’s is, to me, a very, very powerful aspect of the Joker’s lore.

The power of the joker card itself comes from its immutability, meaning that the joker card can be any number that will beat the opposing hand that you pull. It doesn’t have a fixed value. It can be whatever it needs to be to win.

In that regard, it’s scary. It’s wild. Batman comes from an origin, he makes sense of his life, he lives by codes. He’s a being who says, “I will impose a gauntlet of meaning on the world, on my life, so that at the end I will be proud of what I have done.”

I remember so vividly seeing The Dark Knight in the theater and being humbled and inspired, which is the best combination of feeling as a writer. It’s sort of that complete abject terror of “I’ll never do anything that good” and “I have to try to do something that good” all at once.

For us, I think the lesson [from The Dark Knight], wasn’t to use that same version of the character, but to reach as high or to aspire to do a Joker and a Batman that would be that intrinsically opposed to one another and diametrically positioned against each other.

Batman has always been in my favorite character. And the reason that I think he’s so enduring is that he is the most human of the Justice League. He’s a character with no superhuman abilities, and [in a superhuman world] he makes a choice to live by that. He says, I’m one of you, and I’m going to go out there and fight the things that I’m most afraid of, so that you can be brave in battles in your own life.

Our Joker represents pure human evil. He is the belief that deep down we are ugly, dark creatures. And that all of these things that we do give meaning to our lives, the way we narrativize our lives, the way we can say that what we do is consequential, and that we expect of other people, and that we sum everything up as we get old with a sense of purpose.

He says, “That’s all a big joke and I laugh at you. All the things you’re afraid are true, are true.” That there’s no purpose to the world, there’s no design, there’s no meaning. And that the things that you want to do deep down that you don’t do, the selfish, evil things, the dark things that you want to reach for that you don’t reach for, that’s the wasted life. You’ve led a wasted life. And that ultimately it will turn his way.

Like people will, things will fall apart. And it won’t just be chaos the way it was in The Dark Knight. For us it will be evil. People will be selfish and ugly and nasty. And that’s what the Joker is the Pied Piper of. He’s the nightmare figure under your bed, who says the things that you’re afraid of are true about yourself and about the world, those things are true. He’s going to prove it to you and laugh at you while you realize it.

What’s really tricky, and really difficult, is that these characters aren’t just yours. They belong to everybody, and when you write them, you’re shepherding something that everyone thinks is theirs. That means that they are going to be people out there that have versions of these characters in their head that are completely demonically twisted and wrongheaded for those characters, or just in life.

A moment like the Aurora, Colorado mass shooting at a screening of The Dark Knight Rises, stops you, though. Not to make it about myself in any way. The horror was everything that had happened — but as somebody who is working on the character, it definitely gave me pause and made me have to be very careful.

At the end of the day, to me, the Joker is the worst. He is the Devil of the Batman mythos. He is the darkest figure who brings to life the greatest fears of Batman, [and] the creator behind Batman, and for Gotham city itself. So he’s posited as the nightmare, and in that way there’s nothing about him or what he does that’s designed to be celebrated or to be, I think, emulated in any way. He’s the bad guy.

But it’s hard. It is. There’s an intersection of real world and storytelling that happens often with video games, all that stuff. It causes you to really reexamine what you’re doing and to make sure that you’re doing it in a way that’s very true to your purpose. For us, looking at that story and looking at the Joker’s stories we’ve done since, I believe deeply in our interpretation of that character and that what we continue to do with him is appropriate, and hopefully poignant, in terms of the way we positioned him as kind of the worst of the worst.

For me, it speaks to both characters that there’s been a version of both of them for every age. Like when I was a little kid and I loved the ‘60s television show — it was high drama to me. When I was a little bit older, The Dark Knight [Returns] came along with versions of Batman and the Joker that just blew me away. Then The Killing Joke and Arkham Asylum and The Animated Series, when I was in college and all of that, then in the Nolan films, after the Burton films. There was always some version of this relationship that spoke to me as I got older, and now as a dad, a guy who’s not a young man anymore.

If you asked me 10 years ago if I would have a decade’s worth of stories for these characters, I would have said that I just had one — one big one. It’s so, so important. And that’s it. But you realize that this relationship evolves with you and you always have a way, if you want to, of making Batman your hero and Joker your nightmare. Between what we have planned for Joker in Legion of Doom and Batman Who Laughs coming up and Last Knight on Earth...

That’s why I think he’s such an enduring folk hero. It’s a really simple essence. It’s “whatever doesn’t kill you makes you stronger, that sense of whatever it is that you’re afraid of, get up, fight it. And that’s why I think there’s the joke that Batman always wins, and we play with it a lot.

“Who wins in a fight? the Hulk or, Spiderman? Batman wins.” Or the whole joke about “I’m Batman.” That whole kind of celebratory, humorous, ridiculous comedic proclamation. All the time, “I’m Batman. I’m Batman.”

But there’s a real power in those things in the joke that he always wins and the awesomeness of him saying, “I’m Batman.” It’s because he’s the human hero. He’s the one that says, “Yeah, I’m going to be the ridiculous one that gets out there in a Batman costume and fights these gigantic extensions of my own fears to say to you, ‘Whatever you’re afraid of, you can win.’”

That’s why you cheer him on. That’s why it’s fun. That’s why I’m like, yeah, “I’m Batman.” Be Batman. You wear the shirt that says, if you can be anything be anything. Unless you can be Batman, then be Batman. There’s so many shirts like that that people love.

They love Batman for that reason, because he says “Be badass, be you, don’t be afraid of anything. You’ll always win, just like me, because you were Batman.” And that’s it.