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 …

When FBI Agent Zack Stewart is killed, Agent John Ripley takes over the three cases he was working on, hoping one will lead to his killer. The first involves gangster Joe Walpo and Ripley finds his hideout through Joe's …