At the University Seismology Laboratory in Los Angeles, Dr. David Conway demonstrates to his colleague, Dr. Ellis Morton, a new device he has just perfected that can predict earthquakes. When the instrument signals that a massive quake will strike Southern California within twenty-four hours, Conway and Morton fly to the state capital to warn Governor Cheney. Skeptical about the reliability of the untried device, Cheney refuses to evacuate the area. Back at the lab, the scientists’ colleague, Laura “Hutch” Hutchinson, informs Morton that she plans to quit her job to marry her suitor Brad. Morton knows that Laura is in love with the work-obsessed Conway, who is oblivious to her feelings, and advises her to hold out for the man she really loves. Later that night, a massive earthquake strikes, shifting the axis of the earth three degrees. When Conway reports that a series of devastating quakes will occur around the world within the next three to four days, Morton goes to Washington, D.C. to report that a cataclysmic force seems to be expanding within the earth, setting off the temblors. Morton then announces his and Conway’s plan to descend into the Carslbad Caverns in New Mexico to try to locate the source of the pressure. As Hutch, Conway and Morton travel to New Mexico, temblors begin to strike around the globe, tilting the earth even more and causing untold misery. Ranger Kirk of the Park Service, an amateur mineralogist, joins the scientists in the cavern, and upon finding a strange looking rock, takes it to his office to examine it. There, the rock bursts into flames and explodes, killing Kirk. Puzzled by Kirk’s mysterious death, Conway becomes suspicious about the strange rocks. When one begins to smoke and then explodes, he realizes that the mineral killed Kirk and is the cause of the pressure touching off the earthquakes. Naming the mineral Element 112, Conway travels to the Department of Defense in Washington for permission to convene a meeting of every top scientist in the world at the Smokey Ridge Proving Ground near the caverns. At the meeting, Conway shows his peers the element capable of blowing up the earth. Having recently discovered that water reverses the process, Conway advises the scientists to return home and formulate a plan that will neutralize the element, which is pushing to the surface wherever the earth’s surface has been weakened by man’s carelessness and plunder. When word comes that Hutch has been trapped in a cave-in at the cavern, Conway leaves the meeting to return to the caverns. Although her life is in danger, Hutch valiantly continues to monitor the measurements from Conway’s device, predicting that another quake is imminent directly below the cavern. After the ground begins to tremble, Hutch is knocked unconscious by the rubble, and risking his own life, Conway scrambles down the ladder to rescue her. As the earth is pummeled by daily tremblers, Conway feeds his data into the Datatron computer, an electronic brain, which predicts the end of the world will occur in twenty-eight days. Realizing that their only chance of survival is to flood the areas in which the earth’s crust have been weakened, mankind unites to saturate those areas. Panic reigns as the end nears, and Hutch finally confesses to Conway that she loves him and he admits he loves her, too. As word comes that all the imperiled areas have been neutralized by water, a volcano unexpectedly appears in Nevada. To squelch the volcano, the gates to the Horseshoe Dam are ordered open, but when it is discovered that the staff of the dam has been killed by volcanic gasses, Hutch and Conway fly to the dam to blow it up. As they ready the explosives, nitric acid spills onto the element, accelerating the blast and sending Hutch and Conway sprinting to a waiting helicopter. Once they have flown safely away, the dam explodes, flooding the volcano and returning the earth’s gravity to normal. The earthquakes stop, and relieved, Hutch and Conway share a passionate embrace.