There it is, deep under the murky water - a human form. It’s the most stunning find of the excavation, and the divers can barely contain their excitement. Could this colossal figure be the statue of Ptolemy II that guarded his long-lost Lighthouse of Alexandria, seventh wonder of the ancient world?

Join NOVA on an undersea adventure in Cleopatra’s erstwhile capital: Alexandria, Egypt, where a concrete breakwater project is threatening to bury some mysterious stone ruins that lie beneath the harbor. In a race against time, a team of marine archaeologists (granted rare permission by Egyptian authorities) are frantically mapping the harbor floor, salvaging the most remarkable objects with precarious parachute-shaped balloons. What they discover will offer tantalizing clues about Alexandria’s legendary tower- built by the Greeks in 280 B.C. and toppled by an earthquake in 1375- which once rose 300 feet and boasted a brilliant bonfire seen 70 miles away.

Why do so many of the stones- among them sphinxes and columns inscribed with hieroglyphs- date centuries before the Lighthouse was built? The archaeologists’ speculations are intriguing- and the antiquities they produce so impressive that the Egyptian government cancels the breakwater project and to allow a continuation of their curious search.