In the Pacific Ocean, a group of explorers boarded a ship to explore the deep sea. When they were docking, the crew detected an unknown obstacle approaching the deep sea. They urgently contacted the seafarers, but a tragedy occurred. The seabed monitors were eaten by sharks. Six months later, sharks appeared again near the coastal port of Mexico near the Pacific Ocean, and people were unaware of it. A young man who loves diving found a shark tooth in the sea water. The tooth aroused the young man's interest, and he began to look for relevant information. Will sharks really appear in the port of Mexico again? Will people's lives be threatened?