Everyone knows that Pluto is a barren, airless rock. So naturally the Doctor is surprised when he discovers artificial suns and an ultra-modern industrial city. What’s more, a group of colonists is being worked – and taxed – to death in this inhospitable and supposedly undeveloped part of the Universe…. With the help of his companion Leela and the faithful K9, the Doctor takes on the mysterious and powerful Company, a ruthless exploiter of planets and their people.