Fifty-six hard years after the events of The Machine Crusade, after the death of Serena Butler, the bloodiest decades of the Jihad take place. The human worlds begin to hope that the end of the centuries-long conflict with the thinking machines is finally in sight.

Unfortunately, Omnius has one last, deadly card to play. In a last-ditch effort to destroy humankind, virulent plagues are let loose throughout the galaxy, decimating the populations of whole planets. The war that has lasted many lifetimes will be decided in the apocalyptic Battle of Corrin.