The Grand Designs presenter sets out on a mission to find out if a simpler existence really can make people happier, beginning by travelling to a desert island in the south Pacific archipelago of Tonga to meet a British family who have quit the rat race. Karyn, Boris and their three children live in an off-grid property, with no fresh water or electricity and face regular threats from hurricanes and tsunamis. Kevin finds out how they cope with these challenges and the psychological trials of having just one another for company.