I am a great fan of Christopher L. Bennett's work. He's one of those rare authors who attempts to take Trek technobabble seriously, which seems a bit like trying to roll Sisyphus' boulder, yet somehow manages to make things make semi-coherent sense. His Department of Temporal Investigations books incorporate a lot of RL physics to make Star Trek's "time travel runs on the power of plot" almost plausible.
Over A Torrent Sea is the first Star Trek Titan book to take place after the events of Star Trek: Destiny. Despite this, the events of the Destiny series are almost incidental to the book. They're not ignored, Captain Riker wonders why they're not rebuilding the myriad devastated worlds left behind, but the book gives an understandable reason for our heroes returning to their mission of exploration.
Actually, let me take that back, the events of Destiny are very important to the plot but reflects on the more personal losses of the crew as opposed to the widespread destruction the Borg inflicted. Members of the crew aren't thinking about the annihilation of Risa but people they knew who were killed, such as Tuvok's son or a family pet.
This is an interesting way of handling things and perhaps more realistic than leaving the entire crew with a case of PTSD. Star Trek: Titan is about exploration and having only one or two crew members broken up by events seems like a superior way of handling things than changing what the books are about.
My favorite reaction from the crew is the aforementioned trouble Tuvok has with his son's death. His son chose to sacrifice his life to save others, which Tuvok is angry about. No matter how logical the needs of the many are over the needs of the few, a father knows his son chose to die. It's a powerful personal story and one which is handled with both dignity and respect. I also liked Christopher Bennett's handling of Tuvok's wife and would have enjoyed hearing more of her opinions on the subject.
There's also fallout from Troi's pregnancy, which was my least favorite plot from Destiny. I felt her behavior during the trilogy was irrational and unprofessional. Unfortunately, this behavior becomes an actual threat to the crew's stability in this book. For a book series which is more 'realistic' than standard Trek, well semi-more realistic, the fact Troi wasn't packed up and sent home for her effect (however unintentional) on the crew stretched credibility. Still, the adventure which resulted was hilarious.
The main part of the book is another first contact situation where Riker and the crew of the U.S.S Titan encounter a race of Pre-Warp but extremely advanced in biological sciences aliens. This nicely deconstructs one of the elements of the Prime Directive which has never made much sense to me. Why is Warp-Travel the definitive "be end all" of civilization? The Ferengi were sold warp travel when they were primitives while another Pre-Warp civilization might be enlightened pacifists. It's an interesting question that relates directly to Riker's decision to pretty much throw the Prime Directive to the wind this book.
Over A Torrent Sea has a definite "old time" science fiction feel to it. Part of what has made Star Trek: Titan so interesting is the series has focused on developing new and unique cultures for our heroes to interact with. Care and attention is taken to develop the alien's culture, technology, as well as how they interact with their biosphere. Nods are even made to how their world may have evolved. The science is unlikely, but it doesn't mean it's impossible.
I will say, I'm of mixed feelings that the crisis inside the book is as much the fault of the U.S.S Titan as nature. While I suspect the author intended it to illustrate why the Prime Directive is important, i.e. don't go blundering into situations you don't fully understand, I prefer to see our heroes as positive forces rather than negative ones. Even if it's more realistic they'll make mistakes, potentially endangering an entire species is one which hurt my enjoyment of the book.
If I had to say what my favorite part of the book was, I'd definitely say it was developing the character of Aili Lavena as well as the developing relationship between Xin and Melora. The fact I've come to care as much about these 'lower decks' characters as the main cast, says a great deal about how effective the U.S.S Titan series has been in developing them.
Aili's story is about coming to terms with the fact she's a terrible parent, something which is an all-too-human frailty, while a great scientist. You don't usually see that sort of dichotomy and the fact she can't reconcile with her children is a nice way of showing things aren't always repairable. I also liked the contrast between Riker and Aili's attitudes towards sexuality. Riker has always been a gigantic horndog but he's in a committed monogamous relationship and finds Aili's disregard of that (as well as her family) disgusting.
Xin and Melora's relationship is surprising because it's one of the few fictional ones I actually have no idea how will end. Will they end up together? Will they break up? What will happen? Privately, I'm of the mind Aili was right and these two are no good for one another but I'll be interested in seeing how future authors handle it.
In conclusion, Over A Torrent Sea is a great book. It's a story about meeting new life and new civilizations while boldly going where no man has gone before. The fact there's no villains and the problems are purely natural in nature makes Roddenberry's vision stand out all the greater. Was it perfect? No, I had some problems with a few elements and it dragged in one or two places but I overall loved it.