The Doctor is imprisoned halfway across the universe. On Earth, the sighting of a Dalek alerts Ryan, Graham and Yaz. Can the return of Captain Jack Harkness help them stop a deadly Dalek takeover?

In Iceland, Ubbe learns the truth about Kjetill and has a difficult decision to make. Back in Norway, the battle against the Rus has had grave consequences. But re-enforcements have arrived, and Bjorn has an idea that may yet save the day.