Pluto, the distant future. The planet has been terraformed and is now orbited by artificial suns, provided by the rapacious company who ruthlessly exploit the relocated human workforce. The Doctor, Leela, and K9 arrive and befriend a luckless drone worker, but they must flee with him to the dark undercity...

The Doctor has been captured by the Gatherer. Leela works to free him but the Gatherer is already laying his own plans…

Now Leela is the prisoner of the Collector. He knows of the Doctor and is determined to rid himself of both of them.

The Doctor now moves to completely overthrow the Company. But the Collector has one last trump card to play.