This book was really entertaining but definitely not the best place to start for the works of Niven/Pournelle (I'm not sure what Barnes contributed) they seem to be slumming a little bit on the ideas here, the Grendels are the only really new idea and the secret to their life cycle isn't all that impressive and easily dealt with, unlike say the Moties. The beginning scenes with them are great as the authors pour on the suspense and horror but by the end they're just this faceless horde that keeps coming, scary not because they're frightening but because theirs so friggin' many of them. In my opinion it reduces the book to little more than an action movie romp, with the big men strapped on guns and blasting away. Though the strategy stuff is interesting but considering that the Grendels are nearly mindless except for animal cunning, it's not like they're going up against suprageniuses. That and the characters, while drawn enough so you can care about them a little, aren't all that deep, the motivations for coming onto the planet aren't delved into all that deeply. Most of them stick to one type of personality and stick to it without change, heck if I want to read cardboard characters, I'll go get an Ayn Rand novel (ooh, that's one is asking for it, maybe Amazon will delete it to avoid contraversy). But they are sympathetic at least even if everyone seems to think about sex, with or without making babies. Am I being harsh on this book . . . well considering how much better the team has done before, it's probably warranted but at the same time this isn't bad, it's just not as idea driven as the other novel, you sort of check your brains at the door, sit back, relax and have a little fun. It's not even that long. So go try the others first and come to this to see what Niven and Pournelle are like on auto-pilot and you'll see what I mean.