This is the third book in the ongoing Vampire Earth series. Although it is a self-contained episode, I don't think it explains the background well enough to make complete sense by itself. Start with Way of the Wolf.
This book deals with moral ambiguity -- if you have to do evil things to get to a place where you can do things that you must do, how do you live with yourself? Also, if you have done evil in the past that you've rationalized as being what you had to do to survive, how do you go about rehabilitating yourself? In case you were worried that we're getting too deep into morals, though, it does have a lot of running around and fighting and stuff, and it manages to introduce a vampire stereotype that had previously been missing from the series. A new element is added to the mix that will warm the hearts of mad science fans and seem a bit contrived, even considering the world it's in, to the rest of us. And we have a touching noble sacrifice that seemed to be necessary for the story arc to get back to where we were expecting it to go.
It was fun, but a bit weaker than the previous two. 7 out of 10.
**** PLOT HIGHLIGHTS -- SPOILERS ****
Valentine has been working alone, in deep cover, for a year, earning a place in the quisling Coastal Marines for the sole purpose of stealing a ship for a secret mission. He's succeeded better than he hoped, having gained a posting on the Thunderbolt. It's a small gunboat with a couple of machine guns and a cannon, which makes it one of the most powerful warships around, since the Kurians don't believe in navies or ocean travel much at all, and shipping of all sorts has pretty much atrophied in the New Order. Valentine is supposed to be rendezvousing with some other Resistance folks to help with his mutiny, but they fail to show up. He brings Ahn-Kha and his crew of Grogs aboard as laborers instead, and recruits Lt. Post, who has almost drunk himself to death. It seems that Post's girlfriend left him because he was too willing to suck up to the Kurians, and he hasn't really been able to look at himself in the mirror since. Valentine convinces him that he can be useful in the resistance and he goes on the wagon and becomes functional. The mutiny is failing, but a bunch of Jamaican pirates show up and takes the ship, saving Valentine but taking his ship. Carrasca, the woman in charge, is very pleased to have captured the ship. They take it to their home base, and Valentine makes a deal with the boss. He'll take out the Specter, the local Kurian, and in exchange, he gets the boat back for his mission to Haiti. It's impossible, of course, so of course he succeeds. Then the ship, with Carrasca in command and Valentine commanding the marines, heads out. They arrive in Haiti, where the dodgy local human ruler Capt. Boul sells them out to Saunders, but Valentine manages to escape. Then they go overland to meet the enlightened Kurian, who has learned how to survive, though much weakened, without taking vital aura from people. He gives them the secret weapon -- a tree from Kur called quickwood whose sap has an almost supernatural effect on the Reapers. A reasonably fresh piece of wood penetrating close to the heart kills a Reaper instantly. So, yes, the vampires are now vulnerable to wooden stakes. Then they sail from Haiti to Texas. Passing through a huge area of central Texas known as the Ranch, they discover that the Kurians have been trying to breed a more tractable source of vital aura. (It doesn't have to be from humans; any sapient will do.) Unfortunately, the rat-men that they produced are anything but tractable; they rebelled and appear to have taken over much of the ranch. Their command of English is limited, and Valentine mis-interprets the crudely written message they leave behind, only figuring it out once the battle is joined. "Tak and leave woods," left with a pile of supplies, didn't mean "take this and go away" -- it meant "we want to trade this stuff for quickwood". Our heroes manage to make it back to Southern Command territory still in possession of some quickwood. Carrasca and Valentine, who have been sleeping together (when the vicissitudes of their fight give them a chance), nobly decide that each of them has to go back their own place for the good of the Cause and they can't stay together. (Valentine can't stay with Carrasca, since we know he has to hook up with Duvalier eventually...) At the end of the book, Valentine gets a letter from Carrasca, now back in Jamaica. She's pregnant. She's staying with her job in Jamaica, and while she'd like to see Valentine again, she still expects him to stay on the mainland killing Kurians.