On Midsummer's Eve, Dan and Una enact A Midsummer Night's Dream three times over—right under Pook's Hill. That is how they meet Puck, "the oldest Old Thing in England," and the last of the People of the Hills.

Through Puck, they are introduced to the nearly forgotten pages of old England's history and to characters that can illuminate their own historical predicaments. The god Weland is freed from an unwanted heathen immortality by a novice monk, Hugh, who goes on to become a warrior and leader. The centurion, Parnesius, shows an insight which is absent from the higher echelons of the declining Roman Empire in cooperating with the Picts.

Originally published in 1906, this collection of ten stories and accompanying poems were intended for both adults and children.