It has been fifty years since the first Harvest. Hideous creatures, lethal and lightning-fast, were sown into the beds of Earth's oceans eons ago. Now every year, in service to a mad god, they rise from the depths and hunt humans.  Man hides underground in fear of the Harvesters. But he is also sought by other predators: the robots that for years were his companions are now driven to exterminate him in a warped mission of mercy. 

In a race against time, a group of humans cross the United States in a desperate plot to destroy the Harvesters before the next cycle. As if psychotic robots, lobotomized cops and flesh-eating nomads weren't enough of a challenge, they may just invoke the wrath of the ancient god itself...