An earthquake in the Salton Sea unleashes a horde of prehistoric mollusk monsters. Discovering the creatures, a Naval officer and several scientists attempt to stop the monsters, but they escape into the canal system of the California’s Imperial Valley and terrorize the populace.
When a gifted 9-year-old girl, who works in a garment factory, is offered a once-in-a-lifetime chance to attend school, she is forced to make a heart-wrenching decision that will determine her and her sister's fate.