While the topic was once taboo within AMC's post-apocalyptic franchise, The Walking Dead's timeline.

Out of The Walking Dead: World Beyond season 2's ending did the heavy lifting, with most of the relevant details emanating from a single post-credits sequence. Since then, however, Fear The Walking Dead and Daryl Dixon have both dropped subtler tidbits that further illuminate what triggered the apocalypse.

6 The Walking Dead's Zombie Virus Was Made By French Scientists

Revealed In The Walking Dead: World Beyond Season 2

By far the most salient detail revealed about The Walking Dead's zombie virus thus far is that it started courtesy of scientists based in , as heavily implied by World Beyond's aforementioned post-credits scene. Beforehand, The Walking Dead had never confirmed whether the virus occurred naturally or was artificially created, but World Beyond resolved that issue and went even further by pinpointing the outbreak's birthplace to a specific laboratory located in .

There are two primary pieces of evidence that is where the outbreak started. Firstly, French graffiti inside the abandoned laboratory roughly translates to "the dead were born here." And just to rule out the possibility of an artist with an overactive imagination, a mystery figure said to a scientist who returned to the lab in a hopeful attempt to end the outbreak, "End this? You started this!"

Exactly how The Walking Dead's virus escaped the laboratory remains unknown, but World Beyond's lore-shattering post-credits scene offered one small hint. When talking to the stranger holding a gun to her head, the scientist explained how most of her colleagues weren't around when the outbreak began, claiming, "They weren't here when it happened. When you all did what you did." The line is highly ambiguous, but may suggest that the stranger's group were somehow responsible for unleashing whatever the scientists created. That hypothesis remains subjective, but the notion that The Walking Dead's virus was crafted in is hard to disagree with.

5 The French Scientists Responsible For The Virus Had Connections To The US

Revealed In The Walking Dead: World Beyond Season 2

The virus might have been born in , but one detail hints there is blame to share across the globe. According to the scientist from The Walking Dead: World Beyond's post-credits scene, multiple teams were involved in its development, with Violet Team and Primrose Team both named, and Primrose seemingly leading the project. When the virus began spreading in 2010, however, Primrose Team was attending a conference in Toledo, Ohio.

As long as at least one Primrose Team member has survived, hope of curing the virus and ending The Walking Dead's zombie outbreak remains.

There are countless potential reasons for Primrose Team making this trip, but it is curious that a group of scientists developing a pathogen capable of bringing the dead back to life all traveled to a conference in the United States. Given what they were working on back home, one could easily infer that the virus was actually an international effort involving not just , but also the United States and various other global superpowers.

As a bonus consequence of this particular detail, of Primrose Team could potentially feature in future The Walking Dead projects. If the virus' creators were in Ohio when society collapsed, and were subsequently trapped there as airports closed their doors, some of those scientists could realistically be alive 13 years later. As long as at least one Primrose Team member has survived, hope of curing the virus and ending The Walking Dead's zombie outbreak remains.

4 Zombie Variants May Have Been Caused By The Same Scientists

Revealed In The Walking Dead: World Beyond Season 2

When the unidentified French gunman confronted the scientist in The Walking Dead: World Beyond's post-credits scene, he accused her of much more than just creating the virus. After reminding his victim that she and her friends "started this," the gunman followed up with, "Then you made it worse." Considering how this line came immediately before The Walking Dead's first true variant zombie was revealed and the term "variant" was coined onscreen, the overriding implication is that Primrose, Violet, and the other teams made the zombie virus, then developed a version where the undead are faster, stronger, and smarter.

Based on what other shows in The Walking Dead's canon have revealed, the French scientists are not responsible for all variants within the franchise. Daryl Dixon shows how the Pouvoir du Vivant villain group artificially created super-charged zombies out of normal zombies using a serum that must be istered after reanimation, and the same faces were also behind The Walking Dead's burner zombies. Nevertheless, there is at least one kind of variant - the kind that possesses enhanced skills immediately after reanimating - that was seemingly borne from the same lab as the virus itself.

3 Daryl Dixon's Genet Believes The Wealthy Were Behind The Virus

Revealed In The Walking Dead: Daryl Dixon Season 2

The Walking Dead: World Beyond exposed the scientists who physically made the zombie virus, but offered nothing to explain why they did it. Daryl Dixon season 2 is slightly more generous in that respect - albeit only slightly. Genet, the spinoff's main villain and the leader of Pouvoir du Vivant, was a maintenance worker before the outbreak and developed strong anti-rich sentiments during her post-apocalyptic rise to power. As Genet was ranting to Carol about how the wealthy abandoned the poor when the outbreak first began, she described the undead as "the monsters they made."

Genet would be best placed to know the real reason scientists were developing the zombie virus.

With this line, Genet appears to blame the virus on the rich and powerful, and although she may be somewhat biased, her logic is difficult to argue with. The French scientists from World Beyond would have needed funding, as well as a reason to start their research in the first place. To assume the project was ultimately the brainchild of some wealthy benefactor or a coalition of influential politicians is, therefore, entirely reasonable.

Adding further weight to her words, Genet is effectively the leader of when Daryl Dixon begins in The Walking Dead's timeline. More than any other character, she would be best placed to know the real reason scientists were developing the zombie virus within 's borders.

2 One Group In The US May Have Known How The Walking Dead's Zombie Virus Started

Revealed In Fear The Walking Dead Season 8

Most survivors in The Walking Dead, especially those based in the United States, remain blissfully unaware of what started the outbreak, but Fear the Walking Dead may have confirmed that at least one group was privy to such information. In Fear the Walking Dead season 8's " What They Took From You," the leader of the villainous organization known as PADRE argued against rebuilding civilization as it used to be, pointing out, "what we had got us into this mess."

If the US had any involvement in the experiments taking place in , someone once connected to PADRE could feasibly have known.

The line may have been intended in a more existential sense, but did, on face value, give the impression that PADRE knew the story behind the virus. Not even the most deluded antagonist could claim to know how the world got "into this mess" without knowing how said mess was actually made.

Similar to Genet's situation, PADRE knowing about The Walking Dead's virus and the French lab makes logical sense within The Walking Dead canon. PADRE began as a US government operation led by a number of high-ranking military figures. Those leaders were all dead by the time of Fear the Walking Dead season 8, but if the US had any involvement in the experiments taking place in , someone once connected to PADRE could feasibly have known about it.

1 Many Of The Walking Dead's Virus Scientists Have Been Captured Or Killed

Revealed In The Walking Dead: World Beyond

Another major revelation from The Walking Dead: World Beyond addressed where the scientists who created the virus are located during the show's timeline. According to the unidentified gunman from season 2's post-credits scene, his group rounded up most of the responsible parties and either imprisoned or killed them as punishment for their crimes. Some of Violet Team evidently escaped, while of Primrose Team may still be alive in the US, but the rest appear to be dead or locked up in some French detention center for doctors with a heavy conscience.

The larger issue is figuring out precisely which group hunted down and captured these scientists. Logic would point toward the theory that the gunman works under Genet for the Pouvoir du Vivant group, given her apparent control over , but at no point during Daryl Dixon has Genet ever mentioned overseeing a prison full of guilty scientists. Genet has featured extensively across two seasons of Daryl Dixon, with the spinoff providing plenty of insight into her resources, facilities, and followers.

Daryl Dixon has largely ignored the existence of World Beyond season 2's post-credits scene, not once referencing the French lab, natural variants, the scientists, or the gunman.

It feels highly improbable that if Genet captured the scientists who made the zombie virus, that vital slither of information would have gone unsaid for so long. One must, therefore, conclude that an entirely different band of survivors was behind the violent roundup, although whether this unnamed group will ever resurface in The Walking Dead is another matter entirely.