You play as Mike Thomas, one of the very few to survive the end of civilization as we know it. After a biological weapon is wrongly launched, a worldwide contamination begins, causing the death of practically the entire population, while also transforming some into fearful beings.
You get to guide Mike through this dystopia in hope of finding a way to create some sort of society that resembles what once was, while also doing your very best to survive and protect those you meet along the way.
Flashbacks play a great role in the story. As the main plot unfolds in present time, you'll get to play as Mike in a few situations in the past, which will directly affect his abilities and the outcome of certain actions in the future. Choose wisely.