Five years after the events of the first film,[a] Jonas Taylor has been involved in fighting environmental crimes while also helping Mana One in exploring a further deep part of the Mariana Trench where the Megalodon has been found. Following the death of Suyin Zhang, Taylor has been raising her teenaged daughter Meiying alongside her uncle and Suyin’s brother Jiuming Zhang, who has acquired his father’s company alongside wealthy financier Hillary Driscoll. Mana One has also been studying a female Meg called Haiqi, who was discovered as a pup and trained by Jiuming in a reserve in Hainan. Recently Haiqi has been acting erratically, leading to Taylor being concerned despite Jiuming’s enthusiasm.
Taylor and Jiuming lead a routine submersible exploration to the Trench, with Meiying stowing away to see the trench for the first time. Fellow Meg survivors DJ and Mac observe the group from the Mana One. On their way down, the subs are pursued by Haiqi, who escaped captivity the previous night; the subs dive down through the thermocline to escape, but Haiqi forces her way through it anyway. Two much larger Megs, a massive alpha male and a slightly smaller beta male, appear and mate with Haiqi. While working on an escape plan, Taylor and his team discover an illegal mining operation in a station captained by a mercenary Montes, who has a vendetta against Taylor for his imprisonment some time before. Montes’ crew was hired by Driscoll to covertly use the Mana One’s access to the trench to farm rare earth minerals that could earn them billions. Montes kills his crew in an explosion to cover up their activities, which causes a rupture in the trench and grounds both Taylor and Jiuming’s ships.
