Last Friday during Fear the Walking Dead's Hall H panel for Comic-Con International in San Diego, the Q&A portion yielded a question showrunners have fielded ad nauseam since the franchise's inception: Where did the infection that caused the Walker apocalypse come from? It's such a popular query, another fan asked the same question at the Q&A for The Walking Dead panel less than an hour later. And with good reason, too.
One of the things that's made The Walking Dead provocative and terrifying since the first issue of the comics is the element of the unknown that permeates the early years of the series. Rick wakes up and doesn't know where he is or what's going on. When he reunites with Lori and Carl and meets their group, they barely know any more, and they're constantly beset upon by threats they can't anticipate. They also don't understand the new apex predator that literally stalks them day and night, and when they finally get to the CDC toward the end of the first season, Dr. Understanding Diseases is My Only Job is basically, "All I know is we're more f*cked than anyone previously thought."
We do know there is a specific cause to the outbreak -- at least in comics creator Robert Kirkman's mind, but he doesn't have any plans to share it. In press notes for the 2015 premiere of Fear the Walking Dead as reported by Business Insider, he just doesn't think it's that entertaining:
I still maintain that's not an important aspect of the story. I think watching Fear the Walking Dead, you'll get a bigger picture of the world, but as far as digging down to actually find the smoking gun and realizing what that causes, it's really just unimportant to the overall story. If we were to do a companion to The Walking Dead and it was about a bunch of scientists that were working to find the cure and finding out the origins, that would bore me to tears.
That hasn't stopped fans from speculating endlessly on their own, though. Theories have run the gamut to include airborne viruses, poisoned water and even terrorism. An airborne virus or spore is probably the likeliest candidate if we're going for realism -- the virus spread around the world with astonishing speed, which would probably eliminate the idea of some kind of coordinated attack. Unless Thanos was behind the entire thing and TWD discretely became part of the MCU when no one was looking.
But the endless speculation clearly exhausted Gale Anne Hurd, because when asked for what was probably the 14 billionth time, she answered, "The meth from Breaking Bad." Robert Kirkman backed her up saying, "That's canon, it's confirmed." The audience erupted in both cheers and laughter because they were probably joking, but that idea comes from a fan theory that's just interesting enough to make it tempting to believe.
Without going into too much detail, the theory's built on four major tentpoles: Merle's Season 1 stash of drugs included blue meth, Darryl later remembers Merle's drug dealer was fond of calling people "Bitch" just like Jesse Pinkman, in the second episode Glenn drives the same Dodge Charger Walt attempts to give to his son, and Gus Fring walking away from a bomb with a blown apart face means he could've been one of the first people infected with the virus (from his exposure to the blue meth), thus enabling him to "walk" after death.
These are more a collection of Easter Eggs than an actionable theory, but considering it's far from likely we'll ever find out what actually did cause the outbreak, it's one of the more amusing speculative journeys to be had. Especially since AMC seems to be into at least teasing the idea that their shows share a universe. It's not airtight, but considering it came from the lips of Gale Anne Hurd and was later confirmed by Robert Kirkman however in jest, it's the closest thing to canon we're going to get. Whoever came up with this theory has to be feeling pretty good that it was so compelling it had showrunners at least joking it was true.
The Walking Dead returns October 7 for its ninth season on AMC.