The Doctor and the Brigadier attempt to rescue Jo and Bert from the mine but Global Chemicals prove distinctly uncooperative.
Quest roles:
Nicholas Courtney(Brig. Lethbridge-Stewart), Terry Walsh(Doran (uncredited)), Talfryn Thomas(Dave), Jerome Willis(Stevens), Stewart Bevan(Clifford Jones), Tony Adams(Elgin), Ben Howard(Hinks), Mostyn Evans(Dai Evans), Roy Evans(Bert), John Rolfe(Fell), John Dearth(Boss (voice))