The Terran Dominion rules supreme as the only known union of sentient beings in the universe. Only one evolved race of beings has been discovered other than the Terrans - The Ytyl, who have been incorporated into the Dominion as a lesser caste. In the Oort cloud of solar system 22469 a lone science vessel, the Dominion Starship Baxter has received a message which can only have come from a technologically developed civilisation. As the crew of the Baxter attempt to discover the origin of the message, events occur which promise to change the face of the entire Dominion...