A top-secret drilling project descends into chaos when the Doctor and UNIT uncover sinister forces at work. Led by the arrogant Professor Stahlman, this government operation hides dark secrets beneath the surface.
Directed by Douglas Camfield. Written by Don Houghton. Starring Jon Pertwee, Caroline John, and Nicholas Courtney.
Directed by Douglas Camfield. Written by Don Houghton. Starring Jon Pertwee, Caroline John, and Nicholas Courtney.