Because the thief fears his stolen goods might be discovered on land, he hides the treasure chest filled with gold and diamonds safely underwater-tucked away between the seaweed on the ocean floor. But the alert police diver is already on his trail. With his underwater scooter, he darts like an arrow through the deep sea and tracks down the thief and his loot. The officer secures the stolen goods, fastens them to his scooter, and brings them safely back to shore. After the mission is complete, he takes off his fins, arm gear, diving mask, and helmet.