The game focuses on the Tau Fire Warrior Shas'la T'au Kais, a newly-trained member of the Fire Caste seeking to rescue his Ethereal and defend his race from the aggressive assaults of the Imperium of Man and the Forces of Chaos on the Desert World of Dolumar IV.

Unfolding over a period of twenty-four hours, the story follows Kais, a Tau Fire Warrior facing his first mission. That opening assignment is a daring rescue: to infiltrate the prison-fortress of the Imperial Governor Severus and free the captured Ethereal Ko'vash. Kais slips in and escapes with Ko'vash intact, but it proves to be only the beginning. As the Tau cruiser carrying them comes under attack from an Imperial battleship, Kais is pulled into a widening war, fighting through boarding actions and enemy strongholds against the forces of the Imperium. Amid the escalating conflict, darker powers begin to stir behind Governor Severus, drawing Kais ever deeper into a battle far larger than the rescue he set out to complete.