Parts: 4
Writer: Robert Holmes
Airdates: 26 November 1977 - 17 December 1977
Production Code: 4W

Doctor: fourth
Companions: Leela, K-9 mark one

Creature Feature: Usurians

Story: The TARDIS arrives on the planet Pluto - but instead of the barren rock that the Doctor expects, he and Leela find a thriving planet supporting six metallic Megropolises, each with its own sun. Hardly have they arrived on the rooftop of one tall building than they encounter one of the local Citizens, Cordo, preparing to throw himself to the ground, 1000 feet below. He has been driven to this desperate act by the stifling taxation of the Company, which has charged him 17% more for his father's death tax than he had been led to expect - and with the interest the Company charges, he will never be able to pay off the debt with his meagre wages.

All employment on Pluto comes from the powerful Company, run by the Collector, whose talent for numbers is matched only by his gleeful sadistic streak. Taxes are collected by the Gatherer in each Megropolis, and the population is kept under control by anxiety-inducing drugs pumped into the atmosphere. A small group of rebels have banded together in the Undercity to survive, but they seem more concerned with stealing small amounts of money from the Company than with fighting to make a difference.

Naturally, the Doctor and Leela decide that the thing to do is muster Cordo and the rebels to ditch their complacency and mount an offensive against the Company. While the Doctor becomes acquainted with the Correction Centre and the local Gatherer, Leela leads a small strike force to rescue him from the Company's clutches. A horrible death by steaming awaits them if they fail...but can the Doctor overcome the odds and free humanity from the Company's control?