A distress call from a Caribbean freighter leads the NUMA crew to an eerie discovery. The captain lies face down in the bridge. Clutched beneath him - an empty shotgun. Hidden in wait are his shipmates: paranoid, disoriented and ready to fight. Could it be a mind-altering sickness? Or is something much more sinister? The crew's tale takes Kurt and Joe to a cadre of Cuban mercenaries, with a plot to use magnificent modern airships to hijack a nuclear submarine. As the mission moves from the seas to the skies, stopping them could be the NUMA crew's toughest task yet...