Whales lie inexplicably stranded on a beach in the Florida Keys. Overnight a dozen whales, wandering far from their normal migratory route, have appeared from nowhere and beached themselves. More of the creatures are floundering in dangerously shallow water, while a contingent of local citizens and fishermen try to steer them back to the open sea.
Local photojournalist Carol Dawson is sent to cover the story, and after some research identifies a small area of the ocean where, she believes, something must be causing the whales to panic and wander from their normal route.
She hires a boat, and together with its owner Nick Williams goes out to investigate. At first their dive reveals nothing but a perfectly normal looking undersea trench running between two coral reefs, but then they spot more whales, moving aimlessly and sluggishly as if drugged; and when they go closer to investigate they see what looks like a large hole, with metallic-looking lips in the ocean floor; and emanating from the opening, a set of marks that look like tank tracks.....Carol Dawson and Nick Willia,s are about to experience the momentous encounter in the history of the human race.
