An ancient shipwreck. Lost treasure. Buried secrets. Capt. Roy Henry had searched for countless shipwrecks and submerged relics, from a sunken train in a remote mountain lake and lost aircraft in a jungle river to Spanish galleons in the Caribbean. But he'd never encountered anything quite as challenging as his current project. The adventure began when an enigmatic gentleman approached him offering a small fortune to locate a riverboat lost in 1866 in the treacherous waters of Black Canyon on the Colorado River. The river steamer was laden with gold bullion, yet that didn't seem to be the mysterious man's primary motivation. Then, as if searching for a treasure ship didn't have enough problems, an archaeologist from the Department of Interior was now onboard his vessel, claiming an early submarine had been lost on or near the wrecked riverboat. Add to that a troubled 13-year-old nephew under his care, then a ruthless treasure hunter who'd stop at nothing to get the gold, and you have a formula for intrigue and adventure in the historic southwest.