William Shatner is my favorite novelist. He knows how to write action stories that are also very thought-provoking. Shatner's name on a book means that you are going to have a quality read. Avenger is one of his best, thoroughly enjoyable. It is the end of the Trilogy that began with Return. It also preceeds the new series that begins with Spectre. Kirk, Spock, and Picard must solve the problem of the virogen plauge that is wrecking the Federation. Loose ends from previous Star Trek novels and movies are tied up. The book leaves one with a lot to think about with regard to ecology and eco-terrorism. The Federation by homogenizing environments puts the galaxy in danger of being overcome by disease. The story is also very moving and has a surprise ending I will not reveal.