Bron and her friends camp out on top of Nordy Bank, an Iron Age fort in Shropshire. Bron, normally a quiet girl, starts to act strangely and aggressively, as though she were a different person and the sudden appearance of a runaway Alsatian army dog makes them all uneasy. Its arrival leads to a strange sequence of events.

Sheena Porter was born in 1935. A librarian by profession, she worked in libraries in Leicester, Nottingham and Shropshire. Her novels are rich in atmosphere, adventure and characterisation and are often inspired by real places. Nordy Bank is a real place, as are the various other locations including the nearby village of Clee St. Margaret with its well-known ford where the river runs quite a way down the road. Other places feature in her books including Ludlow and Bromfield. Sheena currently lives in Ludlow.