Since debuting in 2003, The Walking Dead has bucked the tropes of zombie movies and reveled in reveals. This was always the mission for writer Robert Kirkman, who, since childhood, wondered what happened to the people who flew into the horizon at the end of Dawn of the Dead. What happened next? The question fueled an open-ended saga that captivated readers and became the least likely mega-rating franchise on television.

On the page, the turns kept coming until the very end. Kirkman surprised the industry and fans by ending the comic this month, with The Walking Dead #193.

“Personally ... I hate knowing what’s coming,” Kirkman wrote in a letter printed in the final issue. “As a fan, I hate it when I realize I’m in the third act of a movie and the story is winding down. I hate that I can count commercial breaks and know I’m nearing the end of a TV show. I hate that you can feel when you’re getting to the end of a book, or a graphic novel [...] The Walking Dead has always been built on surprise. Not knowing what’s going to happen when you turn the page, who’s going to die, how they’re going to die ... it’s been essential to the success of this series. It’s been the lifeblood that’s been keeping it going all these years, keeping people engaged. It just felt wrong and against the very nature of this series not to make the actual end as surprising as all the big deaths ... from Shane all the way to Rick.”

Kirkman appeared at San Diego Comic-Con 2019 with a number of projects, old and new, to talk up. An Invincible animated series for Amazon — a show Kirkman described at the panel as an adult, hour-long drama — is in the works and locking in a cast. His latest success, Oblivion Song, is starting to blossom in the pages of the books. As always, Kirkman said, he’s cooking up hush-hush projects we’ll likely only find out about when they happen.

But the conversation at his solo panel ultimately turned back to The Walking Dead, and the choice he made after 16 years writing the book. In the letter attached to #193, the writer expressed his gratitude to fans for investing in his story and helping him get to the end. He teased an alternate, bleak ending that would have seen Rick Grimes’ legacy consumed by the walkers. But for a comic known for going on and on and on, it wasn’t 100% clear why now. Kirkman offered an explanation to the SDCC audience.

“I never really hit any point where I thought I was going to have to end it or I needed to end it prematurely,” the writer said at the panel. “I know that when I hit issue 100, I had this feeling of like, I can’t believe I’m already an issue #100. I have so much more to do! I have so much more story. I’m so excited. I always knew I was going to end the book, but I really did think I would go past issue #300 at a certain point. I know people criticize the book for being repetitious sometimes, because I go on the internet — I’m human, and I scour the internet until I see things that make me sad.

“But I felt like the story was not repetitious. There was an escalation and something different to every community that they went to and everything that happened because they were learning along the way. But I was acutely aware of how easy it would be to become repetitious. And so that’s the thing that I always wanted to avoid. I didn’t want to get into a place where I was just saying the same thing over and over. I wanted there to be a narrative flow and in order to achieve that you have to have an ending. So I was always in the back of my mind like, wow, how do I wrap this up?

Kirkman said he came up with the ending, which finds Carl and his daughter navigating the future, as well as looking back at the past, shortly after issue #100. “When I saw the cover with the carnival, that’s when I was like, Oh, we’re already doing the carnival and the world is getting better. I can’t have the world be getting this much better here and still make it to Issue #300. I need to find out exactly where this end is going to fall. And that’s when I sat down and did a lot of working out. That got me to #193 perfect. I just couldn’t make it to 200!”

The writer insists there were no extraneous forces influencing his decision to end the comic, despite The Walking Dead being an enormous IP that will never fully disappear from the public consciousness. This is the beauty of creator-owned comics, and the power of surprises.

“The way that Image Comics is set up and the way that Skybound works, you give creators the freedom to create. The fact that there was a TV show and a video game and this massive empire built on The Walking Dead would make it impossible for me to wrap up the drama. But I still had the freedom and control to do what I wanted, including wrapping up the comic in secret and not really telling anybody.”