The West coast of Northern America suffers an unprecedented series of major earthquakes in a matter of days, puzzling seismologists, including Dr. Jordan Fisher's team. His maverick assistant Samantha Hill comes up with a theory, which they confirm on site, that a deep tectonic rift links them and is likely to sink most of California into the Pacific. The only imaginable countermeasure are subterranean nuclear explosions. Three succeed, one rather causes a new problem. Meanwhile federal and other authorities as well as various people wrestle with side-effects like landslides and cope with a huge refugees exodus.