When a devastating earthquake--the Big One--hits Los Angeles, two strangers are brought together by an act of violence and must help each other survive the wrecked city.Beegie is riding the bus when the quake hits. The teenager was heading back to her unhappy foster home, but then she's thrown into a broken world. Roads crumble, storefronts shatter and people run wild.

Dessa, a single mom, is enjoying a rare night out when it strikes. Cell towers are down, so without even knowing if her three-year-old daughter is dead or alive, she races to get back across town.

As danger escalates in the chaotic streets, Beegie and Dessa meet by a twist of fate. The two form a fragile partnership, relying on each other in ways they never thought possible, and learn who they really are when there's only one goal: just get home.