A castle, a deserted village, and murder in the Scottish Highlands

When child psychologist and US Naval Intelligence officer Lieutenant Peter Dunbar takes on a secret mission in the Scottish Highlands at the end of World War II, he finds himself drawn into the lives of a troubled boy and his beautiful young cousin.

But why does Johnny Stockton refuse to explain why he keeps running away from his comfortable home? And how might the answer be entangled with the mystery of an escaped German prisoner and a dying man's message?