Dr. Robert Ballard is one of the world's most renowned ocean explorers, with such amazing finds as the Titanic, the battleship Bismarck and JFK's PT 109 to his name. But this time he is going on a journey like no other. He's going to make an underwater odyssey down the world's tallest mountain! No, it's not Everest at 29,000 ft. It's Mauna Kea in Hawai'i. Standing 13,800 ft. above sea level, this Pacific Giant also reaches down another 19,700 ft. into the Alien Deep. Fighting unimaginable pressures, Ballard leads a two-submersible team right into the volcanic heart of the island and comes face to face with extraordinary creatures never before captured.