Written by David Whitaker
From a Story by Kit Pedler
Directed by Tristan DeVere Cole
The TARDIS materializes on board a spaceship, the Silver Carrier, where the Doctor and Jamie are attacked by a maintenance Robot. Jamie manages to contact a nearby space station known as the Wheel and they are rescued. Though viewed with suspicion by many of the crew, the Doctor and Jamie befriend Zoe Heriot, a young prodigy with total recall and broad scientific knowledge, as well as a healthy ego.
Meanwhile, the Silver Carrier discharges Cybermats, which travel to and enter the station. These pave the way for the penetration of the station by Cybermen, who intend to use its direct radio link with Earth as a beacon for their invasion fleet.
The Doctor sends Jamie and Zoe over to the Silver Carrier to fetch the TARDIS's vector generator rod. Meanwhile he manages to free the Wheel's crew from the Cybermen's hypnotic control and to destroy all the Cybermen on the station.
When Jamie and Zoe return, he installs the rod in the station's X-ray laser, making it powerful enough to destroy the Cyber-fleet. Zoe joins Jamie and the Doctor in their travels.
The Cybermen return in what has to be their worst story to date. At this point, the base under siege formula has absolutely been beaten utterly into the ground by the production team, and not even David Whitaker, one of the series best writers, or Tristan DeVere Cole, a solid and even inspired director, can save this utterly unremarkable story.
There are things to enjoy here, from some very good visual effects to DeVere Cole's inventive camera movements, to a supporting cast that all do their job well. But at this point, we've seen this story so many times that there is almost no surprises here. The Cybermen invasion force is depicted via two Cybermen stalking around the Wheel. While their plan is pretty effective, there's not enough for them to do to stretch across six episodes and the whole body horror roots of the monsters are pretty much gone by now.
The best part of the whole story is the introduction of Wendy Padbury as Zoe. To me, the Doctor, Jamie and Zoe are the classic Troughton era team, and Zoe's naive arrogance creates some lovely sparks with her two new cast mates.
It's a shame that she debuts in what has to be the worst serial of the season, and a poor way to end what has been overall an excellent if formulaic season of Doctor Who.