I have only just encountered Watts's work. This book is a crashing tangle of ideas, drawing from evolutionary biology, to (most particularly) cognitive science and philosophy of mind of the late 1990s.

A ship, whose crew are all variously transhuman in diverse ways, are sent to communicate with first contact. The newcomers, however, are deeply mysterious, alien in the realest sense. The result a disorienting experience in which none of the available main characters are quite someone you can wholly empathise with, and we remain uncertain throughout of just what the encounter will involve for the crew or humanity generally.

My perception overall is this book, with its extensive references and sources section, is the kind of thing you might get if Michael Crichton wrote space opera (though perhaps more disciplined and sharper). It is jam packed with well executed ideas. Ultimately, I found it quite difficult to get through in parts simply because of just how utterly out of their depth everyone was, and how desperate and hopeless the contact mission would seem to be. I suspect this is indeed Watts's intent.

While it was nice to see the richness of the cognitive science being drawn on, my own theoretical commitments also mean that none of what is in play with regards to human cognition is really tenable though. That's a very niche complaint that most of the world won't have. A little more broadly is the easiness of the some of the evolutionary psychology though - some of which is I think a little problematic.

Overall, though, this is a very solid, well written space opera thriller, if a little grim.