While the Doctor plans a holiday to Metebelis Three, Jo and the Brigadier are intrigued by a mysterious death at a coal mine in Llanfairfach, which is being blamed on local company Global Chemicals.
Did You Know?
When Dai is alone down the mine, telephoning for help, a crew member's arm is clearly visible moving in the bottom right corner of the screen. He may be signalling the actor to start. See more
Referenced in People Power and Puppetry