A group of children set out on a seaside picnic that becomes an extended adventure when they reach a remote island showing signs of past habitation. Weather forces them to improvise shelter and provisions; they explore nearby coves and islets, encounter natural hazards, and investigate traces of smuggling and unexplained coastal fires. The narrative follows their practical tasks—foraging, hunting, and building a wickiup—while developing resourcefulness, cooperation, and problem-solving as they face setbacks, a significant disaster, and the effort to get their launch home and conclude the outing.