The Walking Dead: 10 Twists You Never Saw Coming
5. Everyone Is Infected
When Rick and the group first arrived at the CDC at the end of the first season, everyone's hopes of a vaccine were destroyed when they learnt that not only was there no vaccine, but also every world government had likely fallen apart. There was going to be no rescue effort and the dead weren't going to be going away anytime soon.
However there was the added mystery of what Dr. Jenner whispered into Rick's ear as they fled the self destructing lab. It wouldn't be until the end of the second season that we actually found out what Rick learnt. Everyone is infected. This was a huge revelation. Not only was it quite a unique take on the zombie virus, seeing as usually a bite was required to turn into a zombie in other medias, it also meant that no matter what you did, chances are you'd end up as a walker.
It changed the entire nature of the show. Season one dashed the hopes of a Government rescue and the end of the second season made it clear that the walkers were going nowhere. There's something quite horrifying about the revelation that everyone is infected, and only the comic readers could have seen it coming.