The Stranger in the Lifeboat by Mitch Albom

Adrift in a raft after a terrible shipwreck, ten strangers struggle to survive while they wait for rescue. After three days, short on water, food and hope, they spot a man floating in the waves. They pull him on board – and the survivor claims he can save them. But should they put their trust in him? Will any of them see home again? And why did the ship really sink?