Spoilers ahead--according to the recently-aired series finale of Walking Dead: World Beyond, the zombie outbreak in the franchise was apparently manmade.
In a post-credits scene that is completely unrelated to the events of Walking Dead: World Beyond, an exchange spoken in French between a gunman and a doctor--no name is given for either character--medical researchers in France were inadvertently responsible for both starting--and worsening--the zombie apocalypse we've all come to know and love
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