Returning to the darker themes of Tiger in the Smoke, Allingham introduces a serial killer who is haunting London's Theatreland. The sparring between Sergeant Luke (who thinks he's got the case sewn up) and Albert Campion (who wonders what the old couple on the bus saw) is sparkling as ever, but readers will note that Allingham was shifting toward psychological themes that put her in the company of Ruth Rendell and Patricia Highsmith.
