Tsubute, Paperback by Archer, R. J., ISBN 0977910911, ISBN-13 9780977910915, Like New Used, Free shipping in the US

When the NWIDI team travels to southern Japan to investigate an underwater pyramid off the coast of Yonaguni, the adventurers find themselves involved in murder and international kidnapping. In an effort to clear their names, they uncover a dark secret hidden on the tiny island for more than 10,000 years.