In some ways, this book deals with all the issues that sequels to space operas with mysteries deal with - now that we know what is going on, where is the suspense?
Fortunately, "will our intrepid heroes survive to wisecrack some more?" has never let anyone down as a plot and it keeps this series moving here as well. Pratt has a good sense of the balance between mystery and reveal and the snarky, scrappy spacefarers are just fun.
Four stars instead of three for not doing the thing where it turns out that some people are irredeemably evil and you should never trust because you'll always get screwed over. Seriously. Less GOT, more Sam Gamgee.