Two and a half centuries ago, Sir Henry Morgan, a notorious British Naval Admiral and privateer, invaded Panama twice. His objective was to disrupt the movement of gold and other riches from Panama to Spain. Specifically, he wished to capture a priceless golden altar, which was the centerpiece of Cathedral Tower near Panama City. Morgan, who was feared for this brutality, used Catholic priests and nuns called the Religious as human shields as he and his men advanced into the city, destroying everything. On his second raid, the Religious took matters into their own hands. They climbed to the top of Cathedral Tower, where they joined hands, said a prayer, and leaped to their deaths as Morgan and his men entered the city. This summer, 'Snail' Cali and his girlfriend, Teri Silva, have decided to take a summer ecology course in Panama sponsored by their university. They are excited about the adventure and the proposed diving itinerary. While in Panama, they are fascinated by the history and ruins of the famous Cathedral Tower and the mystery of the missing golden altar. Unfortunately, their trip is plagued by a series of unprovoked attacks on their group. While they manage to fend off a variety of assailants both in the city and while diving, they eventually discover that their old and presumed dead nemesis Mr. Chang is the mastermind behind the attacks. Will Mr. Chang finally get his revenge on Snail and Teri?