Cave Dweller (Jack Ferrell Adventure Book 3)

Marine biologist Jack Ferrell is out on Kauai's rugged northern coast when he sails into a strange fog that glows in the dark, a phenomenon he never expected in Hawaii. Through the mist he hears a young woman calling for help and rushes to aid her. The following morning, while checking reef damage caused by a drift net, he makes an unexpected find beneath the water: a sunken Japanese mini-submarine from the attack on Pearl Harbor. Nearby, in a hollow in the coral, lies a human skull unlike any fossil he has seen. A colleague links it to a small, extinct species, and Jack gathers a team to explore a hidden world inside the mountains, where the questions about the skull lead toward the islands' legends.