Citadel

York was hundreds of light years beyond the edge of human space. His starship was badly damaged and several of his crew were dead. But he had traced the path of the Visionary Ships and now was orbiting the planet he believed to be Earth, home of the human race. Echo didn't consider herself to be human. She had been constructed in a laboratory and a quarter of her genome was alien. Earth meant nothing to her, but she had left too much destruction behind her to return to the Empire. All she had left was her captain and crew and she would stop at nothing to protect them. The crew of the Citadel had risked everything to find out why the Sleepers left Earth to found a new civilisation so far away. The ship was picking up a signal, but it wasn't human.