The world's sea levels are rising at an alarming rate, too quickly to be caused by glacier melt. A risk so big it sends Kurt Austin, Zoe Zavala and the NUMA team rocketing around the world in search for answers.

Their hunt takes them from the shark-filled waters of Asia to the high-tech streets of Tokyo to a forbidden secret island, but it's in the East China Sea that a mysterious underwater mining operation is discovered. 

Kurt uncovers a plot more dangerous than they could have imagined: a plan to upset the Pacific balance of power, threatening the lives of millions. It falls to the NUMA team to risk everything to stop it and save the world from the coming catastrophe.