A routine dive for shipwrecks off the Mediterranean coast at Atlit, Israel turns into the discovery of a lifetime for maritime archaeologist Ehud Galili when he stumbles upon the perfectly preserved remains of a 9,000-year-old settlement, Atlit Yam. Among the findings: a megalithic stone circle, twice as old as Stonehenge. Who were the people who built this remarkable monument? Why did they do it? And what rituals were held here? A remarkable breakthrough in DNA technology may answer these and other questions surrounding this mysterious find.