Sally's team must negotiate with their new arrival to see what they should do to repair history, but soon find that they are working at cross purposes.  The nature of their problem now looks yet more hopeless.

Window in the Sky

Episode 15 An Uneasy Ally

With a lasting peace established between Earth and Baltan mediated by the growing alliance with the mysterious Szzzyyyxx, a new chapter in human history begins. But in the midst of this, the Szzzyyyxx Mother requests Sally's help with a mystery. Two Szzzyyyxx vessels have disappeared in the far reaches of their space. Sally and Ian plan a controversial rescue mission with the first of a new line of experimental ships. They arrive in the region to discover a fold that doesn't appear to go anywhere. On closer inspection, however, they find evidence of a black hole and a strange world that defies understanding. Through the use of a machine established in eternity, The Szzzyyyxx have teleported to Earth in the 1960s. There, captured by the KGB, they unwittingly help a rogue agent rise to power and dominate the Earth. But the power he uses to do this opens a door to something far worse. With their own past erased, Sally and her crew must rebuild history and defeat an ancient and universal evil.

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Window in the Sky