Episode Two
Series Episode Number: 351World Premiere: Sat 26 May 1973 - 5:50pm BST [BBC One] (United Kingdom)
First Broadcast: Fri 21 Nov 2014 - 8:30pm EST [Retro TV]
Running Time: 25 minutes 56 seconds
7.20 Million (UK)
Chart Position: 38 () (UK)
Recorded on Tue 03 Apr 1973 in TC3
Archive State: PAL 2 VT
Investigating the old mine workings, Jo and miner Bert become trapped beneath the surface when the lift is sabotaged. Bert touches some green slime and becomes infected.