William and Luke continue their investigation into who was really behind the events that led to William's exile, and become ever more convinced that the person in question is from the future. But before they can discover anything further, unknown alien entities start swarming the time stations, killing anyone in their path. When the entities are also found to have consumed all life on Earth in the past, William and Luke take the time ship Dynasty and its crew back to 1909 to try to prevent this invasion of Earth from ever taking place, though they only have a narrow window of opportunity to do so. They discover that the being from the future that they've been trying to find is responsible, and is willing to go to any lengths, including genocide, to prevent Temporal Security or anyone else from getting in their way.
It quickly becomes evident that the perpetrator has much more significant plans than merely using time travel for smuggling when an invasion fleet of heavily armed starships approaches Earth in 2509. All of humanity is overshadowed by this threat, including the colonies in other sectors of space. With the survival of humanity resting on their shoulders, William and Luke must find a way to fight this enemy who has more advanced time travel technology than even Temporal Security. And there's also the question of the admiral's wife, Larissa, who seems to know more about what's going on than she's willing to say.
