A Reggie Fortune crime enterprise by the author of The Queen of Spades. The setting is wartime England and the story is launched with a country fire followed by an enemy bombing and the hitting of a factory. Two people die -- two American soldiers are suspected -- and strife between American troops and British stationed near breaks out. The title refers to a clue -- a cat's whisker -- to international espionage and murder. Fair -- but diffuse in style and execution.