Coral reefs are the greatest living organism of this planet. They are the lung which permitted life to exist on Earth for hundreds of millions of years. But today something has changed. The coral reefs are dying. Should this happen we would be witnessing history's latest terrifying mass extinction. An event at which we would not just be simple spectators, we would be the victims. Who is killing this planet's lung? Three young scientists, Federico Fanti, Grace Young and Vanessa Loveburg are hot in pursuit. But how can a geologist and paleontologist, a robotic engineer and a marine biologist find the killer of an organism which does not follow the rhythms of human beings? By studying the crime scene; which is exactly like the one which has been taking place before our very eyes for millions of years. The one which transformed an ancient coral reef into rock: the Dolomites. The Dolomites are the key to understanding the evolution of coral reefs and to averting an apocalypse. From Washington DC, in the headquarters of the National Geography Laboratory, where Grace is designing marine drones for 3D scanning of coral reefs (and possibly also future exploration of planets like Europa and Encelado), to cost in front the Saadani National Park in Tanzania where Vanessa is studying the sickness of coral reefs on the island of Montserrat, to the beautiful scenario of the Dolomites, the "crime scene" but also an inexhaustible source of clues and beauty. These three scientists, with the help of the latest technology, will face the spectator with a horrifying truth: we are killing our planet. But not all is lost. There is a way of saving the coral reefs. And it is buried in the breathtaking views of the Dolomites.