Splashdown (Through the Fold) (Volume 4)

Sally's life on Earth becomes boring when she turns to politics, but not for long. As UN space commissioner, Sally finds herself presiding over the aftermath of Earth's first colonial war. Baltan City, Earth's greatest achievement, tries to declare independence, which creates a violent and polarizing conflict. In the midst of this new cold war, an Earth ship from the future is entering the system and appears to be approaching Baltan. Sally and Ian must call a truce with the colonists long enough to investigate. The ill-fated mission launched 20 years after the day Sally Buds sets foot on Baltan involves the testing of an engine capable of creating its own fold. The results were disastrous. The crew of the Alliance ship Ultrablitz is still alive, technically, but they've been in transit for 1300 years in an attempt to stop their own mission. But, on further investigation, it becomes clear that there is yet more at stake and than one ship, and it falls upon Sally to decide the fate of thousands of people across the centuries.