When Sir Robert Boniface, industrial magnate and self-made man, is found shot dead in his blue limousine near Hampstead Heath, the journalists and police of London are set astir. As Inspector Mooney begins to build up the case, a barrage of obstacles come to light in the form of painters with grudges, Soviet Union agents and the mysterious comings and goings of a very important pistol. A London-focused mystery with a strong 1930s interwar period feel.