We've found the Fireflies (or they found us). This was what we were looking for all along, until we find out that the only way to create a vaccine is to extract what's keeping Ellie from turning out of her body. This will leave her defenseless to the infection though and will kill her. Joel's not having that and he's back to looking for Ellie. To get to her though he'll have to get through all of the Fireflies.
The game follows Joel as he helps escort Ellie across the United States in a post-apocalyptic time. It begins with a zombie like outbreak that leads to the disaster.
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