A diving excavation in the waters beneath Venice turns deadly when three divers are killed by a great white shark. The expedition was funded by Clemenza, a mysterious Italian power-player. In Berkeley, California, professor and world-renowned underwater archeologist DAVID FRANKS is informed his father, one of the divers, is missing. David and his fiancée, LAURA, fly to Venice in search of answers.
At the Venice morgue, David and Laura learn the “official” cause of death for two of his father’s colleagues is a propeller accident. David has seen shark attacks before and knows the truth is being hidden. He decides to dive in search of his father’s body, though the local police captain wants to keep the news of sharks a secret. Before the dive, David goes to his father’s apartment and discovers it’s been ransacked. However, he finds what the intruders could not - his father’s research -- he had been searching for the lost treasure of the Medici Brothers (three knights from the eighth Crusade of the 13th Century) who had stolen King Solomon’s precious stones, metals, and artifacts. These brothers were killed and their treasure lost for all time.
Using his father’s research, David dives under the city. He finds his father’s watch just as sharks approach. David defies death... escaping the sharks, though he is bitten on the arm. He swims through an underwater labyrinth and finds a chamber - the hidden catacomb of the Medici Treasure. With his arm bleeding badly, he barely makes it out of the canal alive. In the hospital, Laura tries to convince David to leave the city.
However, the corrupt Clemenza and his men will do anything to recover the treasure and therefore prevent David and Laura from leaving Venice. As the two avoid danger at every turn, they discover that Clemenza is responsible for the unusual presence of sharks in the canals of Venice. He brought the beasts to the city to prevent anyone else from diving for the treasure. Unfortunately,