When bombs are dropped over parts of the world, everyone is in terrible danger. No one knows who did the bombing, but whoever it was...they are long gone.
They left everything in shambles, not many people survived the blasts. But some...did.
Mark wakes up in his home, he leaves the partway broken house and walks to the street, no people anywhere. He's in danger if he stays alone, so he goes in search of anybody. And he has no idea what has happened.