As a series of earthquakes start tearing apart Los Angeles, scientist Emily of the USGS theorizes that it's all building to a super quake that will drop the entire city into a lava-filled chasm. Engineer Jack, whose company is responsible for the quakes due to their deep fracking, feels obligated to help, and races with Emily through the increasingly damaged city with the hopes of diverting the epicenter to a less populated area, potentially saving millions of lives.