The Tardis lands on Earth in 1985 after an urgent call. The doctor (Colin Baker, the sixth doctor) finds himself having to transport a group of Cybermen back to their own planet. During this trek, he discovers that the Cybermen are preparing to crash Halley's Comet into Earth to obliterate the planet. This memorable DOCTOR WHO episode features a shape shifting Tardis, which turns into a pipe organ, among other objects.