When massive volcanic storms begin to spew from the Earth, geophysicist Kate Ferris tries to convince the Department of Defense that this is no natural phenomenon. They're the result of a seismic super weapon known as the Hell Storm device; and now that it's been activated, the shockwaves it sends out will destroy major cities across the globe, killing millions. When her claims fall on deaf ears, Kate teams up with her daughter and estranged husband at the San Andreas fault line to find a way to counteract the destruction. As Kate and her family navigate the fault, they find themselves directly at the epicenter of the largest shockwave yet. Now, in a harrowing race against the clock, Kate must figure out how to stop the shockwave before its effects seal humanity's fate once and for all.A stolen seismic weapon is activated in Yemen. A hostage freed there tries in vain to warn against its global effect. It starts seismic activity at the Californian fault line where her daughter and ex are monitoring it. Can they stop it?