It's time for goodbyes. Fitz is going on an expedition to Siberia with with paleontologist George Williamson, and Anji is finally going home. All is not well, however. The Doctor knows something about Fitz's expedition that he refuses to say, and Anji is finding home life and her old routine are not as comforting as she had hoped. There is a man with a terrible power that he can't control, threatening more than just his own life, and the CIA are investigating time anomalies, and closing in on Anji.
Tropes present in Time Zero include:
- Doomed Expedition: The Williamson expedition is lost with basically all hands.
- Hyperspace Arsenal: Actually justified. Clothes that are bigger on the inside are useful for more than just super-effective Spanx. Although they are useful for that, too.
- Ignorant of Their Own Ignorance: When the Doctor learns that Sabbath is involved, he demonstrates how Sabbath's view of time travel doesn't work; Sabbath believes that just travelling through time immediately creates a new past or future where the time traveller appeared versus where they were never involved, but the Doctor demonstrates a Stable Time Loop where he solves a problem by creating a scenario that only works because he already set up the necessary chain of events to help him fix things.
