The tau are a mysterious alien race, diametrically opposed to the Imperium of Man in every possible way, from their mastery of technology to their methods of warfare and social structure. Yet in galactic terms they are a young race, and naïve when it comes to the manipulations of Chaos. When promising young commander Farsight is promoted to lead a crusade across the Damocles Gulf to reclaim the tau's lost colonies from mankind, the mood is one of optimism. With their mighty fleet, and superior weapons and machines, how can their endeavour possibly fail? However, despite a parade of early successes, Commander Farsight soon faces enemies he wasn't anticipating, and finds not only his courage but also his soul tested to the very limit.