The jagged backbone of Europe, spanning seven countries and providing essential water to millions, the Alps are Europe's most important landmark. But how did marine fossils get here, seven thousand feet above sea level? A team of investigators as far back as Leonardo da Vinci attempt to fathom out how the Alps evolved, a story that takes us to the bottom of the sea, up the slopes of the infamous Eiger and Matterhorn and deep into the heart of a glacier. But these iconic peaks won't be here for long. Mountains are tumbling down, glaciers are melting and the Alps are being washed away.