At a Navy research facility in Big Sur, an astounding breakthrough in interspecies communication takes place. Communicating through code and only partially understood by the scientists, a bottlenose dolphin warns of an impending environmental disaster. Unfortunately, the revelation is immediately covered up and misused by U.S. government political interests. A militant environmental group soon emerges with its own political agenda and its own methods for correcting the environmental threat. Soon, the militants are blamed in the sinking of a U.S. ship, and sharks suddenly behaving as if they are doing their bidding ravage American beaches. Cuban leaders are implicated in these acts, and military action against Cuba becomes, according to those who hope to profit by it, a strategic necessity. Then, when a large group of dolphins appear to become willing instruments of the militants, a government plan to exterminate all dolphins in United States waters gains popularity. Mayo Richardson, former professional diver, with a teen-aged daughter, and a bogged down publishing career becomes the unlikely liaison between the dolphins and the government. As a child in Cuba Mayo had a mystic encounter with a dolphin and believes them to be intelligent, spiritual creatures. Haunted by this memory, he later wrote a book about his beliefs. Now, saddled with doubt and by his feelings for Renee, an attractive scientist assigned to work with him, Mayo dodges terrorists and government agents in an odyssey that rushes him from Kansas City to Big Sur to the Indian Ocean. Wherever Mayo goes, he finds little support for avoiding the growing threat of environmental catastrophe. In one last desperate attempt to awaken incredulous officials, he journeys to Sri Lanka and into the heart of the million-year-old dolphin civilization. There, in a cave under the Indian Ocean, Mayo finds a way to focus the world's attention on the greatest potential disaster in human history, and also discovers how to get his own life back on track.