NUMA researcher Hiram Yeager has discovered that the toxic ordnance was also carried by a Japanese submarine lost in the South China Sea. Pitt Jr. joins his sister Summer and father aboard a NUMA salvage vessel that locates the wreck, but Tongju and his commando team seize the vessel. After taking the recovered toxin and kidnapping Pitt Jr and Summer, the North Koreans sabotage the salvage ship and leave the imprisoned crew to drown, but Dirk is able to help everyone escape.