An oil company using fracking has set the stage for disaster by causing a series of mini earthquakes near the San Andreas Fault. Jack, an engineer with the company, rushes to warn his family only to find out his teenage daughter is heading toward the danger zone with a group of friends. Emily, a geologist on her first day at work, is convinced that the small tremblers hitting downtown are building up to a super quake that will dump the entire city into a steaming underground cauldron of fiery magma. Jack and Emily frantically race against time to avert "The Big One."