Karen is interested in history, so when she discovers a mystery about the long-dead convist, Simon Patterson, she can't resist going off to pursue answers, even though camping and hiking are not really her thing. Her two brothers love the outdoors and their grandparents let them go along with the neighbours.
The children travel across country for a week. Conflicts, bad decisions, weather and distractions they find what they are looking for and learn some life-lessons (1950s style) along the way.