The spaceship is the Halo Genera. Its occupants, which include four humans, two bio-engineered synthetics, and an obstreperous robotic assistant named Larry, represent mankind's last-ditch, desperate but bold attempt to save the human race from extinction. Their destination: Despond 5, a planet light-years away from what was once home. But, as so often happens when manned spaceflight is matched with cutting-edge exploration, things don't go according to plan. Plagued by system malfunctions, subterfuge, sabotage and malevolent aliens, the Genera's crew race towards their destination. But can they reach it in time to save the human race?