I finished this book last night and think it was better than "Third Exodus".
Basically,and without giving away any spoilers.
We have people living on Mars and they still want to discover more of space.And they also want a new vehicle for
said space exploration.It is possible there is a partial vehicle on Earth and it would save alot of time building one from scratch.
In the meantime people have gotten together,some children are born.
And you learn more about the A.I. "Walter".
A solid 4-star read.