An experimental time machine, one of the first designed by the human race, crashes into the TARDIS. The First Doctor finds himself on a strange island. Later, his companions end up in East Berlin in 1966.
The story begins with Steven, Sara and the Doctor drinking champagne to celebrate Christmas, as seen in The Feast of Steven, the seventh episode of the epic television story The Daleks' Master Plan. This places the previously released Sara Kingdom audio adventures after The Anachronauts.