"Thank God it's only a motion picture," the caption on the box reads. Dana Andrews stars as Doctor Steven Sorrenson, head of Project Inner Space, an initiative to bring magma to the surface under control. When the lowest layer of the Earth's crust frustrates his efforts to penetrate it, Dr. Sorrenson seeks permission to use an atomic device, convinced the heat of the blast will easily burn its way through to the mantle. His project's geologist and young wife's ex-flame, Doctor Ted Rampian (Kieron Moore from "The Day of the Trifids") develops the 'Rampian theory,' the belief that the crust has been so weakened by years of underground atomic testing, that this bomb might open a crack in the Earth's crust. Finding out he's terminally ill, Dr. Sorrenson overrules his geologist and successfully fires the warhead. But soon after both scientists investigate strange seismic phenomena, and it becomes apparent that the Rampian theory no longer is a theory: a nearby fault has opened up and is threatening to circumnavigate the globe. Released in 1965, the movie enjoys some rather impressive special effects, and I like the way the music emphasizes the action. I personally think very highly of this film, and it's my belief that it must have become the inspiration for the Doctor Who episode "Inferno."