Kate O'Donnell, fresh from her adventures in Dead Beat, discovers yet again there's a darker side to London in the Swinging Sixties. Beatlemania has reached London, but young photographer Kate O'Donnell soon discovers a darker side of the city when a prostitute is found murdered off the Portobello Road. A West Indian immigrant, Nelson Mackintosh, is arrested, and simmering racial tension reaches breaking point. Convinced of Nelson's innocence, Kate determines to track down the real killer. But when her activities attract the attention of notorious gangster King Devine, not even Kate's old sparring partner DS Harry Barnard can ensure her safety.