The year is 1944; the war hangs in the balance. In deep retirement in the English countryside, the 90-year old master of detection (never called by name) has not been called on to exercise his superb gifts for some years. His famous reputation has faded, and the locals think he's more interested in his bees than in he is in his fellow man. Into his life steps a nine-year-old Jewish refugee boy, an escapee of the German concentration camps. The boy is mute and otherwise notable for the blue German-speaking parrot which perches on his shoulder wherever he goes. What is the meaning of the strings of German numbers the parrot spews forth? Might it be a code? A diverse and not very respectable set of interested parties is becoming increasingly eager to find out what secret the parrot holds. Then the parrot goes missing, and a body is found.