Harvey Zane was forced to kill pirates to protect the national undersea treasures but then got wanted. On the way to flee to the sea, he saved Yale Larkin and Tina Wood who fell into the sea and who met a shark. But later, they grew very interested in Harvey's ship and liked to explore it. For fear that his murder was exposed, Harvey asked them to leave. However, Yale and Tina pushed Harvey into the sea... Would Harvey perish in the sea? And would Yale and Tina find Harvey's secret?
