Roger, the son of a Norman lord, is the very first child to live in the hose that much later becomes known as Green Knowe. One day while wandering the hills near the great house, Roger comes upon two ancient stones, shaped like chairs, hidden under some brush. He calls them King and Queen. Even more mysterious than their presence is what happens when Roger sits on the stones. The King Stone brings him forward in time, and the Queen Stone sends him back!
Roger uses this magic to reveal the fate of his beloved home, which he wishes would stay as it is forever. The Green Knowe he visits in the future is startlingly different, but the children who live there--Toby, Linnet, Susan and Tolly--all welcome him warmly. Roger teaches these children, who live centuries apart from one another, to use the stones so they can all gather together at once and experience marvelous time-traveling adventures as he does.