The Changeling is set in ancient Britain, where a small tribal group known as the Epidii lives along "the flat coastwise strip below the place where the Glen of the Chariot-Crossing opened towards the Western Sea." The Chieftain's wife has just become the proud mother of a baby boy. He is the seventh born to the families living in the Chieftain's big house. The oldest man in the tribe predicts disaster.
Long ago before the Epidii came, the "little Dark Folk" had been been the only people living in the glen. "But their slender weapons tipped with the dark blue flint had been no match for hard cutting bronze swords, and spears tipped with the magic grey fire-metal called Iron. And so the Epidii had driven the Dark People away into the barren moors and waste places, and made their own settlements on the good land." The Epidii know that when it's time for the Dark People to sacrifice a child to their gods, they sometimes steal a seventh child from the Epidii to sacrifice instead, leaving their own child with the Epidii in its place.
But what happens to the changeling left with the Epidii? The story grows more interesting when Tethra the changeling becomes old enough to think for himself. He has never been completely accepted by the Epidii. When hard times come, he causes conflict just by existing among them. He makes a life-changing decision. Though not Sutcliff's best work, The Changeling is an engaging tale her fans will appreciate. (1974; 86 pages of large type. Recommended for preteens.)