Plenty under the counter - Kathleen Hewitt

David hesitated. He knew the story well enough. He knew what had happened on the sunny Sunday morning of the outbreak of war, when the papers were too packed out with real news to have more than a line or so for the sudden death of the old Marquis of Leafe, in a flat in Jermyn Street. He knew that Miss Trindle had been the book-keeper at that shady block of flats, and that she had arrived in Terrapin Road within two hours of the Marquis's death . . .

London, 1942. Flight-Lieutenant David Heron, home on convalescent leave, awakes to the news that a murder victim has been discovered in the garden of his boarding house. With a week until his service resumes, David sets out to solve the murder. Drawn into a world of intrigue and double-dealing, he soon realizes that there is more to the inhabitants of the boarding house than meets the eye, and that wartime London is a place where opportunism and the black market are able to thrive. Can he solve the mystery before his return to the skies?