Many things in the world of science fiction, come from the reality of science itself. Man has always thought, if there was some way to harness the hot volcanic magma in the center of the earth, it could supply the energy needs of the entire world. In this film, a top Geo-scientist, Dr. Stephen Sorenson (Dana Andrews) plans to use a nuclear tipped missile to punch a hole into the crust of Earth's mantle and release all the energy stored therein. His colleague, a former student of his and rival for the affections of the heroine, Maggie Sorenson, (Janette Scott), is Dr. Ted Rampion (Kieron Moore) who warns emphatically that such an explosion could cause a gigantic, world-wide catastrophic 'crack' in the earth's surface which could destroy it. Alexander Knox plays Sir Charles Eggerston one of many members of the Earth's council, whom Sorenson eventually convinces of the safe feasibility of the project. The film is highlighted by magnificent explosions and dramatic action scenes which prove, this movie should have garnered more attention when it dominated the marquees of the day. All in all a great cult film for all ****