Full synopsis can be found below:
UNIT is called in after a miner from the Welsh village of Llanfairfach is found dead, his skin glowing bright green. Jo joins forces with a local environmental group, led by Professor Clifford Jones, while the Doctor investigates the nearby plant of a company called Global Chemicals.
They discover that the mine workings are full of giant maggots and green slime – both lethal to touch – that have been produced by chemical waste pumped from the Global plant.
This special edition features improved remastering techniques and expanded special features.
The RRP is £20.42 but you can pre-order it from the BBC Shop now for £13.99.