Thursday 28 May 2071: the day the Anglo-Indian Salvage 2 rocket launches. Its mission: to clean up space; to remove from Earth’s orbit over a century’s worth of man-made junk…

From the viewing window of a nearby space station, the Doctor and Flip have a unique view of Salvage 2 as it sets about its essential task – and of the disaster that unfolds when Salvage 2 encounters something it’s not been programmed to deal with. Something not of human manufacture…

Back on Earth, the Doctor fights to save Flip from becoming part of a 500-year tragedy being played out in orbit, hundreds of miles above. And millions will die if he fails.