It’s 1979 in the International Decade of Ocean Exploration. On a training cruise off San Diego, marine technician Neil Bricker and journalism student Cate Rosario witness the discovery of a substance that could transform the nation’s energy economy. Neil joins a private expedition to validate the find and Cate decides to write the story. They become unwitting partners in a criminal conspiracy that subverts the expedition. Meanwhile, Neil and Cate are distracted by their own failing love affairs until it may be too late to avoid disaster. The final reckoning leaves it mark on the deep.