The author does a good job of getting everyone to a single place for a showdown, but in the end it is not very satisfying. Setting up a planet to blow and having it easy to shut down is a big plot hole. But worse is the fact that all the casualties among the main characters are all weak-willed men (or at least, their female companions are portrayed as stronger than them). It is basically the same thing as if the genders were switched so it is as unsatisfying. Really the weakest of the three books in the series, though of course the necessary conclusion.