The Doctor is making adjustments to the TARDIS' coordinate programmer in preparation for a visit to the blue planet of Metebelis Three, when Jo reads in the paper about the mysterious death of a miner named Hughes in the abandoned coal mine in Llanfairfach in South Wales: The miner, doing a monthly inspection of the bottom of the mine shaft, emerged dead and glowing bright green. Jo takes this opportunity to meet the acclaimed local environmentalist and Nobel Prize winner Professor Clifford Jones; while Brigadier Lethbridge-Stewart goes down to investigate the miner's death, taking Jo with him in his car. The Doctor agrees to follow the Brigadier, but is determined to go to Metebelis Three first.
The Brigadier's first port of call is the recently opened Global Chemicals oil plant, close to the abandoned mine. Its headman, Stevens, claims that the plant can "produce 25% more petrol and diesel fuel from a given quantity of crude oil" - but that the 'Stevens process' only produces a minimal amount of waste. Jones, in his environmentally friendly retreat the 'Wholeweal', (nicknamed the "Nuthutch" by the locals), is convinced that the oil-making process must create thousands of gallons of waste. He also believes that there is a link between Global Chemicals and Hughes' death - but his research is too demanding for him to go down the mine and investigate. Jo, who is on the environmentalist's side, heads for the mineshaft.
The Doctor reaches Metebelis Three, but it is far from the "blue paradise" he described: He is attacked by various unseen creatures, returning to the UNIT laboratory with only a small blue crystal to show for his misadventure. He then drives down to South Wales in his car, Bessie, and meets the Brigadier at Global Chemicals. The two then set off to go down the mine to investigate, despite Stevens' insistence that the mine should be sealed. Stevens summons his henchman, Hinks, and tells him in a strange emotionless voice "nobody must go down the mine". Hinks leaves and Stevens dons a pair of strange headphones.
The Green Death Special Edition signed by Katy Manning DVD