Almost every major culture includes an ancient flood story. What if evidence of the Great Flood could be found? Join Dr. Robert Ballard, discoverer of the Titanic, on an odyssey to find the submerged truth about the Great Flood. Dr. Ballard sets off to look for ancient shipwrecks, and search for evidence supporting a controversial theory that links the legend of the Great Flood with the catastrophic flooding of the Black Sea around 5500 B.C. As his sonar scans the desolate sea floor, and robotic submersibles search the haunting darkness of the Black Seas dead zone, the truth begins to emerge from the murky depths of myth and legend.