The Open Door — Laurence Meynell

Stella Brendan was accustomed to a comfortable unearned income and she was fifty-two years old when it vanished. How could she survive? She could survive by marrying Sir Loder Cholerton, tycoon and ageing bachelor. But Stella has skeletons in her past, skeletons that would not appeal to Sir Loder should they come out. When that threat occurs Stella calls Hooky Hefferman, who finds himself trying to protect Stella's interests. Then there's a murder. A man has been shot and there are several people who could have fired the fatal bullet ... 'Thoroughly civilised writing, managing to up-date the easy, humorous, engaging mood of pre-war days, floods this pleasant country house mystery with a sunny glow' Glasgow Herald