The Purgatory Squadron's survivors have done the impossible; by traveling through time they've shut down the impenetrable Wall that cut the solar system in two. In doing so, they've discovered that the rebellious Colonization Industrial Companies have hidden a satellite in Earth's orbit that could destroy the planet just as the CIC eradicated Uranus. But the Purgatory Squadron has a trump card. Now stranded three days in their own past, they just might be able to return to Earth without notice. That gives the team of outcasts and criminals three days to stop a cataclysm that could bring about the first universal war.

In the midst of a latent civil war between the core planets and outlying planetary settlements, an immense wall has cut our solar system in two. The black wall absorbs all light and matter, and it's up to a band of soldiers facing court martial to investigate the phenomenon. They're the men and women of the Purgatory Squadron. For which crimes are they here? And can they work together long enough to stay alive once they enter... The Wall?