The first part is a race against time to survive. The second part is a war between humans for scarce resources in space. The third part is about humans, who a

The first part is a race against time to survive. The second part is a war between humans for scarce resources in space. The third part is about humans, who are largely doing fine, finding out stuff about the past and themselves. There are some deadlines & urgency in the last part, but I think it's a tall task to try and create urgency when the previous sections were about the entire human races being extinguished.