A group of scientists at an underwater research facility off the coast of China encounter a 75-foot-long prehistoric monster shark called a Megalodon. They enlist the help of Jonas Taylor, an experienced diver, to rescue their stranded crew members. As they track and poison the shark, they discover it is smaller and younger than the one they've been hunting. They face intense confrontations with the shark, resulting in sacrifices and deaths. Ultimately, they succeed in killing the shark and celebrate their victory, ensuring the safety of the oceans.

A research team led by Jason Statham and Wu Jing embarks on an exploratory dive into the ocean's deepest depths. However, their mission takes a dangerous turn when they come across a malevolent mining operation. Now, they must battle colossal Megs and relentless environmental plunderers in a high-stakes race against time.