The Wheel in Space - Plot

Plot

The explosion of the mercury fluid link forces the Second Doctor and Jamie McCrimmon to evacuate the TARDIS to avoid mercury fumes, and until the mercury can be replaced, the craft is marooned. They find themselves on a space vessel, deserted apart from a Servo-Robot. The robot detects the intruders and in response redirects the rocket from aimless wandering. The shock of a course change causes the Doctor to hit his head, briefly concussing him. The robot also releases a group of egg-shaped white pods into space, and the mysterious things direct themselves toward a nearby spaceship shaped like a giant wheel, attaching themselves to its exterior by a seeming act of will. When the robot becomes aggressive, Jamie succeeds in destroying it, but the Doctor is very weak and collapses.

The Wheel is an Earth space station observing phenomena in deep space and is staffed with a small international crew. The crewmembers are concerned by the sudden drops in pressure, which, unbeknown to them, coincide with the pods attaching themselves to the exterior of the Wheel. Controller Jarvis Bennett is also worried that the Silver Carrier, a missing supply vessel eighty million miles off course, has suddenly turned up nearby and is not responding to radio contact. He decides to destroy it with the Wheel’s powerful x-ray laser.

Jarvis is only prevented from doing so when they hear a deafening burst of noise from the vessel. Jamie has managed to alert them to his presence aboard the Carrier and shortly thereafter he and the unconscious Doctor are both rescued and taken aboard the Wheel. While the resident medic, Dr. Gemma Corwyn, sees to the Doctor, Jamie is given a guided tour by the sparky young parapsychology librarian, Zoe Heriot.

Gemma knows that Jamie is lying, so Bennett remains suspicious of the new arrivals, fearing they could be saboteurs opposed to the space program. He decides to use the x-ray laser on the Carrier now that the two refugees have been rescued, little realizing that the TARDIS is still on board, but Jamie intervenes, sabotaging the laser with quick-setting plastic.

Meanwhile, aboard the rocket, two pods similar to the ones which attached themselves to the Wheel draw energy from around it. A three fingered silver hand punches its way out of the top of one of them.

Jamie's sabotage of the laser only further infuriates Bennett, especially as there is a potential meteor shower heading for the Wheel – and they now have no way to repel it. As a result of this Jarvis confines Jamie and the Doctor to the sickbay. When the Doctor recovers he does not approve of Jamie's action. He also remains groggy and unclear, but convinced that a major danger lurked on the Silver Carrier. Zoe has calculated that the ship did not drift to their sector but was deliberately piloted there. The Wheel’s crew, however, are more concerned with the impending meteor shower.

It turns out that the two large pods contain Cybermen, who discuss their plans with the Cyberplanner (an immobile unit which is in control of the Cybermen) over a video communicator. The small pods they sent to the Wheel contained Cybermats and these have been sent to begin consuming the bernalium rods in the Wheel’s stores. The bernalium is essential to power the x-ray laser. The Cybermen have deliberately engineered the star in Messier 13 to go nova, thus forcing the Wheel crew to look to their bernalium stores only to find them missing. When this happens the Cybermen expect the crewmen will instead come to the Silver Carrier for an alternate source of bernalium, which can then be transported into the Wheel – with a surprise inside.

Engineer Bill Duggan has indeed noticed the depleted stocks and the presence of the Cybermats. His delay in reacting allows another crewman, Kemel Rudkin, to fall victim to the Cybermats. Jarvis Bennett overreacts with panic to this state of affairs, briefly stripping Duggan of his position and imposing tighter controls. The Doctor has a more practical solution – he uses the x-ray machine to scan a floor plate which Rudkin had sprayed with quick-setting plastic, revealing a Cybermat. Jarvis sends two crewmen, Laleham and Vallance, to the Silver Carrier to look for bernalium. Once there, the Cybermen reveal themselves and take control of their minds. They then order Laleham and Vallance to take them to the Wheel and help them.

Laleham and Vallance are used to prepare the bernalium crates destined for the Wheel with two Cybermen hidden inside. This ruse works and the crates are soon aboard the Wheel. The Doctor and Jamie try to warn Dr. Corwyn and Bennett, but the controller does not accept the danger. Indeed, Dr. Corwyn, who has formed an alliance with the Doctor, fears for Bennett’s mental state, as he seems unable to deal with escalating events. Over time his behaviour seems to be becoming more and more bizarre and detached from reality.

Duggan and Leo Ryan are glad to have access to a new power supply for the laser, which they are slowly repairing. An engineer called Chang is killed by the emerging Cybermen when he is sent to fetch the new bernalium supply. They dispose of his body in a waste disposal incinerator. Laleham and Vallance arrive at the laser with the bernalium supply for Duggan, who also falls victim to the same mind control process and becomes the third agent of the Cybermen. Duggan is sent to destroy communications with the Earth. He smashes the control panel and gets shot by Leo Ryan.

The Doctor has meanwhile deduced that the fortuitous supply of bernalium has a deeper significance. He has also reasoned that the late Duggan was being mind controlled and instructs Dr. Corwyn to use a basic transistor system attached to each of the crews' necks as a means of repelling this technique. The Doctor and Jamie go to the loading bay and discover the crate's false bottom, which confirms the presence of the Cybermen aboard the Wheel. Behind them, a Cyberman is coming down the steps.

The Cyberman leaves with some bernalium, not detecting he Doctor and Jamie. However, they are then ambushed by Cybermats. The crew use a sonic wave to disable all the Cybermats aboard the Wheel. Gemma and Zoe show Jarvis a dead Cybermat, but he refuses to believe that they are under attack. Gemma relieves Jarvis of his command as he's obviously unfit to be the station controller.

The death of Duggan is no obstacle to the Cybermen as another engineer, Flannigan, is found to replace him. Laleham is killed trying to subdue Flannigan when Vallance misses with a gun. A Cyberman takes control of Flannigan's mind. The Cybermen have invested time in repairing the x-ray laser, evidently needing it ready for use. Thus when the meteorites are finally due to hit they can be deflected and obliterated. The Cybermen want the Wheel intact so they can use its radio beam for their fleet to home in on. They want to invade the Earth, desperate for the planet's mineral wealth.

The human crew have managed to fully repair the x-ray laser and use it to defend against the incoming meteorites. The Doctor decides that he needs the time vector generator, which he earlier removed from the TARDIS. Jamie and Zoe are chosen for a space-walk to the rocket. Gemma shows them to the airlock, but hides in the oxygen room. She overhears Vallance and a Cyberman plotting to poison the air supply, and warns the Doctor before she is killed by a Cyberman. Meanwhile, Jamie and Zoe are caught up in the meteor shower.

Leo switches over to sectional air supply, meaning that the Cybermen cannot poison their air. Shocked back to consciousness by Gemma's death, the insane Jarvis Bennett is killed when he seeks revenge. Leo assumes control as the Doctor warns there is a vast Cyberman spacecraft heading for the Wheel.

The Cyberplanner suspects that someone aboard knows of their methods. Vallance identifies everyone on board, and the Cyberplanner and Cybermen recognise the Doctor. The Cyberplanner decides that the Doctor must be killed. Jamie and Zoe tune into this conversation aboard the rocket and go back with the time vector generator to warn the Doctor.

The humans need to contact Earth, but Duggan's suicide mission made this impossible. They need spare parts. Flannigan pretends to be normal and says he will meet up with the Doctor in corridor 6 and give them to him. This is a plan by the Cybermen to ambush the Doctor and kill him. The Doctor suspects this and so goes through the air tunnels to the power room to fetch them. When the Cybermen don't find him in corridor 6 they order Flannigan to go to the control room and destroy the forcefield.

Jamie and Zoe get back, and Flannigan takes them to the control room. He is overwhelmed by Leo and Enrico Casali, the communications officer, and his conditioning is broken. The Doctor is cornered in the powerhouse by the two Cybermen and they reveal their plans to him. When they try to destroy him he electrocutes one with a machine he wired up. A large group of Cybermen start spacewalking towards the Wheel. Jamie and Flannigan go to the loading bay and free Vallance from cyber-control. Flannigan uses quick-setting plastic in a fire extinguisher to kill the last Cyberman, and then turns on the deflector shield, which deflects the Cybermen into space. The Doctor uses the time vector generator to boost the power of the x-ray laser and is successful in destroying the advancing Cybership.

With the invasion repelled, the Doctor and Jamie return to the Silver Carrier with the mercury they need to repair the TARDIS. They are accompanied by Zoe, who quietly stows away as the time vessel departs. She is determined to stay and so, to warn her of the dangers ahead, the Doctor uses a mental device to project images from his mind to the viewscreen, which tell her of his and Jamie's encounter with the Daleks in their search for the Dalek Factor.