The city of Venice attracts millions of tourist each year with its rich historic and artistic heritage. Behind the beautiful and vibrant facade, lies a city in grave danger. The Adriatic Sea that brought fortune and glory to the city is also a threat to Venice and its lagoon. When the sirens go off, Venetians brace themselves for an incoming attack. The tide rises, floodwater rushes into the city and destroys every artwork or architecture in its path. Expert teams of Engineers, Scientists and Conservators are determined to save this UNESCO World Heritage site from vanishing beneath the waves.