Riding a Log to Nowhere: Jan Mark, Voyager. London: MacMillan, 2006.
This is Jan Mark's last book and it is painfully obvious that it was intended as a middle book in the trilogy that began with Riding Tycho (2005). It begins with Demetria's rescue from the water and the log on which she has escaped her island, and follows her as she is captured, rescued and begins to prepare to be sent back to her island as an agent of the underground. We learn a little more about her planet--Demetria--and that the war between the two inhabited continents is over whether to exploit the third continent as technological development begins to speed up.
And that's it. The politics of the world are barely sketched. There is not enough dissonance to really estrange us. This could be an argument over Alaska. Although Demetria is highly intelligent she is also utterly dependent on what she is told.. she sees almost nothing of the society she lands in as she spends most of her time in a safe house. So in turn, we too learn nothing.