The Green Death

Near the Welsh village of Llanfairfach, a miner, Ted Hughes, returns to the surface after inspecting the local disused coal mine and sounds the alarm. When he is found, he is dead, and glowing bright green. UNIT are therefore called in to investigate. They have also been asked to provide protection for Global Chemicals, a local factory which is being blamed for the closure of the colliery and so the loss of jobs in the area.

While The Doctor makes a trip to Metebelis 3 alone, Jo decides to join Professor Clifford Jones, a Nobel prize winning ecologist, and his group at The Wholeweal Community - known locally as 'the Nuthutch'. As The Brigadier is visiting Stevens, the chief of Global Chemicals, he offers Jo Grant a lift.

Professor Clifford Jones is concerned about the pollution that Global Chemicals' processes are creating – despite their claims to the contrary. Stevens explains to The Brigadier that their processes create no pollution or waste, but Clifford Jones tells Jo that this cannot be the case. Jo guesses that they must be pumping the waste down into the old mine-shaft and so decides to investigate. After the strange death of their colleague a miner, Dai Evans, also decides to investigate the mine. However, he shortly calls for help as his hand is glowing green. Jo arrives and descends into the mine with another miner called Bert.

Metebelis 3

The Doctor, who has just arrived after a harrowing trip to Metebelis 3, and The Brigadier are too late to stop them. They then discover that the lift has been sabotaged and the brake does not work. They manage to halt the cage before it reaches the bottom of the shaft – leaving Jo and Bert trapped in the shaft. In order to get down into the shaft themselves, they need to cut the cable. This they eventually do but only after obtaining some cutting equipment from a nearby garage as Global Chemicals, who they approach first, claim not to have any. When the cable has been cut, so releasing the other cage, The Doctor and Dave Davies, another miner, descend down the shaft.

Meanwhile, Jo and Bert have decided not to wait when they realise that they are very close to the bottom of the shaft. They therefore decide to try and find another way out. They come across a flow of slime down a wall, which Bert touches with his hand. This causes his fingers to start glowing green. His condition soon worsens so Jo goes on alone. The Doctor and Dave Davies soon arrive and find Bert. While Dave Davies takes him back to the surface The Doctor goes on until he finds Jo. However, they become trapped when the roof falls in. They then discover a large pool of slime, in which can be seen hundreds of giant white maggots and so have to use an abandoned mine cart to reach the other side. They then make their way up an old disused shaft which emerges in Global Chemicals' factory. On their way up the shaft, The Doctor finds a giant egg which he takes with him. They emerge in a room to discover that Global Chemicals are flushing their waste down into the mine and so are the cause of the green slime and the giant maggots.

Jo with Professor Clifford Jones

On returning to the Nuthutch, The Doctor and Jo inform The Brigadier of what they have discovered. After an evening meal they all, except for Jo, retire to bed. However, the egg The Doctor found hatches and a large maggot approaches Jo, who is alone reading in the living room. She is saved by the sudden arrival of Hinks from Global Chemicals, who has been ordered by Stevens to retrieve the egg. The maggot attacks him before escaping into the garden.

This convinces The Brigadier to summon UNIT troops to the area and to bomb the mine workings and seal them. Even with the mine shafts sealed, the maggots start to emerge via other routes: the shaft leading to Global Chemicals and the slag heaps surrounding the colliery. When it is discovered that bullets have no effect The Doctor realises that a biological weapon is needed. To create one he needs to get some oil waste from the factory and so poses as a milkman and a cleaning lady to get inside. Once inside the factory he meets Captain Mike Yates, who under the orders of The Brigadier, has infiltrated Global Chemicals as a visitor from The Ministry. He tells The Doctor about a special lift to the top floor.

When The Doctor reaches the upper floor of the factory he discovers that it contains a large and powerful computer calling itself BOSS (short for ‘Bimorphic Organisational Systems Supervisor’) which is linked to Stevens' brain and which is totally self sufficient. The Doctor finds himself trapped and being brainwashed. But this does not work and so Stevens has him locked up. Captain Mike Yates though releases him so allowing him to escape. Captain Mike Yates stays on so that he can learn more about what Stevens is up to.

A Giant Maggot

Meanwhile at the Nuthutch Clifford Jones is trying to find something to kill the green infection. But Jo accidentally spills some fungus powder on Clifford Jones’ microscope slides – ruining them. As she feels that she is just in the way Jo decides to get a maggot for Cliff's experiments and heads for the slag heaps. When she has gone, Clifford Jones realises that the fungus powder Jo spilt has neutralised the green infection. He then realises where Jo has gone and, with The Brigadier calling for an RAF strike on the area to try and kill the maggots, Clifford Jones rushes to the slag heaps to stop Jo. He eventually finds her just as the bombing starts. They are forced to head for an old mine entrance to escape from the bombing and the maggots all around them. But when the Professor is caught in an explosion he is knocked unconscious.

Realising where they are The Doctor and Sergeant Benton rescue Jo and the unconscious Clifford Jones from the slag heap. But back at the Nuthutch it is realised that the Professor has a glowing green stain on his neck. He mutters about serendipity, but no-one knows what he is referring to. While The Doctor tries to find an antidote to cure Clifford Jones. The answer comes from Nancy who finds a dead maggot by the fungus. The Doctor realises that it has been killed by eating it. Sergeant Benton and The Doctor distribute the fungus from Bessie and they start to die. However they soon discover that one of the maggots has pupated into a giant fly which attacks them until The Doctor uses his cloak to bring the creature out of the sky.

When Jo asks The Doctor what serendipity means he explains it to be a lucky accident; she recalls that she spilt fungus on Clifford Jones's slides. Realising that the fungus is the cure to the sickness as well, The Doctor leaves Nancy and Jo to look after Clifford Jones while he returns to Global Chemicals as he has just discovered, from Captain Mike Yates, that BOSS and Stevens plan link all the computers in the world together so that BOSS can then control them all. They will then be able to take over the whole world and so must be stopped. Using a blue crystal, obtained from Metebelis 3, The Doctor frees Stevens from BOSS' influence so allowing him to activate a self destruct sequence. The Doctor has just enough time to run from the factory before it explodes.

With BOSS destroyed, the threat of the giant maggots gone and with Clifford Jones recovering The Doctor finds that Jo wants to go with the Professor on a trip up the Amazon rather than return to UNIT with him. When Clifford Jones then asks Jo to marry him and she agrees The Doctor is saddened, but wishes her well and gives her the blue crystal as a wedding present. As a celebration party starts up, The Doctor is all alone and so departs in Bessie.