The spinoff series have broadened the scope, offering glimpses into the global impact of the zombie outbreak. However, it is “The Walking Dead: The World Beyond” that unravels the franchise’s deepest secret. In the post-credits of its Season 2 finale, viewers are transported to a French biomedical lab. Here, a woman frantically searches dusty cabinets for computer drives. As she watches an old recording from Dr. Jenner, played by Noah Emmerich from the Centers for Disease Control, a man confronts her with a gun. He accuses her and her colleagues of creating the zombie virus. Before more can be revealed, he shoots her, only for her to rise as a zombie.

This scene links back to the inaugural season of “The Walking Dead,” though its broader implications remain somewhat ambiguous. Despite being a pivotal reveal, the origin story is easy to overlook within the series. Notably, it’s a departure from the origin narrative hinted at by creator Robert Kirkman in the comics.

Hints about the virus’s origins have been subtly woven into “The Walking Dead” since its inception. The first season concluded with the survivors reaching the CDC in Atlanta, where they encountered Dr. Jenner. He shared a grim secret with Rick, revealing that while the virus’s source was unknown, every living human was infected. Consequently, death inevitably led to reanimation as a walker.

“The Walking Dead” has been hinting at the origin of the zombie virus since the show’s earliest days. Season 1 ended with our survivors arriving at the CDC headquarters outside of Atlanta. There they meet a scientist named Dr. Jenner who tells Rick a terrible secret about the virus. Dr. Jenner dies, but Rick eventually reveals his secret in Season 2. The doctor didn’t know where the zombie virus came from, but he did know that every living human on the planet had already been infected with it. Everyone who dies is doomed to become a walker.

Now we know that Dr. Jenner was actually in communication with the French lab that started it all. Does that mean he, or some of his fellow scientists, were getting close to a cure? That was certainly something that Dr. Jenner and the woman investigating the research facility wanted, but now that all the scientists are dead, their research is virtually useless.

We know from the overall “Walking Dead” timeline that zombies are still roaming the Earth more than a decade after the collapse of civilization. For most of the people still alive, the origin of the virus doesn’t matter anymore. The post-credits scene from “The World Beyond” does include some hints about the zombie variants that would later appear in the “Daryl Dixon” series, but the scene’s most dramatic reveal has almost no impact on the franchise as a whole.

There are some things that only comic book fans know about “The Walking Dead,” and for a long time the origin of the zombie virus was one of those — sort of. For years there were hints and jokes in the pages of “The Walking Dead” that the infection might have come from space. Then in 2013, there was an issue that included a short side story called “Small Bites,” written by Derek Hunter, that addressed the origin head-on. “Small Bites” made it clear that an alien ship crashed on Earth and inadvertently instigated the zombie apocalypse.

“Small Bites” is clearly written outside the normal style of “The Walking Dead,” and because of that it’s tempting to write off the alien origin story as a joke. If it is a gag, though, it’s one that series creator Robert Kirkman is very committed to. Kirkman was asked in 2020 about the zombie virus origin by a fan on Twitter, and the writer stated plainly that zombies were created by a space spore. Kirkman is also the creator of “Invincible,” so fans know that he does have extraterrestrial threats on the brain — just don’t expect aliens to appear in the TV show version of Kirkman’s zombie universe anytime soon.