In a remote Florida lake, a cave collapses, trapping Doc Ford and two of his friends. Ford manages to escape and surfaces to find help-but two ex-cons are waiting for him. They're intent on diving to the bottom of the deep lake and finding the remains of a legendary plane, supposedly loaded with gold. Ford's expertise is just what they need. And if he doesn't help, Ford and his friends are dead in the water.

Sneaking an underwater look at a notorious Russian black marketeer's fancy yacht, Doc Ford emerges to discover that the marketeer's private island has been taken over by environmental extremists who threaten to kill a hostage every hour until their demands are met.