Out on the moors in the early morning to draw a picture of the ancient Stones of Arden, eleven-year-old Scottish Robert meets Jennifer, 12, a transplanted American who wants to be an archaeologist and hopes the stones will be her Stonehenge. Through a mist both children are transported through time to the same post-technological future visited by four British children in In the Keep of Time (1977). There they meet Kartan, a boy their age, and other members of a peace-loving society threatened by Barbaric Ones who are rounding them up for slaves. ""What use is it for us to believe that trust, love, and sharing are real forces in the world, only to abandon that belief when we need it most?"" asks one of the adults--who later intervenes and beats a Barbaric One who is about to strike Jennifer. That's about the extent of Anderson's philosophy, and the plot follows a fairly standard time-fantasy path aimed toward evading Barbaric Ones and getting back to the present. However, it is all accomplished without strain, and Robert is sufficiently well drawn and likable for readers to share in his viewpoint.