The Last of Us franchise is a story of humanity trying to survive in the face of a virus turning people into fungus creatures that are not quite zombies. We learn early on in the first game that Ellie is immune, perhaps even the only immune person there is. This makes her invaluable to those trying to find a cure. Except, I think she may not be immune. The second game shows a lot of evidence that something else may be going on with Ellie. Something that may tell us the future direction of this story and the future of Ellie.