Hurricane Mabel is far out in the Atlantic Ocean and moving slowly northwards. Perhaps it will never come near land at all. But if it hits the island of San Fernandez, many thousands of people will die. There could be winds of more than 250 kilometres an hour. There could be a huge tidal wave from the sea, which will drown the capital city of St Pierre. Mabel will destroy houses, farms, roads, bridges... Only one man, David Wyatt, believes that Mabel will hit San Fernandez, but nobody will listen to him ...