While walking along the beach one day, Isobel and Nicholas discover a strange looking wreck. As they begin to put it together, they find it is a peculiar sort of sailing boat. They clamber in, and so begins their great adventure. Aided by a wounded stork, they sail through the sky, encountering scenes of despair and devastation, and set about righting some of the wrongs in the world. At each place they stop to help, and soon the boat is full with all their new friends - a bullied girl, a weak child worker, a boy, rescued from a polluted city, a mother and baby saved from a war zone. But, this all takes its toll on the boat, and they have to find a safe place to land, where they can all work together to build a bigger and better sailing boat and continue on their humanitarian mission.