Miss Hewitt Investigates the Man in the Tree — Linda M. Stephenson

It is London 1915 and Great Britain is at war with Germany. Stylish lady detective Miss Isabel Hewitt is approached by a young soldier Captain Alex Fraser in the hope of finding his natural mother. He was given away at birth. Isabel agrees to take on his case even though she suspects the mother may be a friend of hers. Her inquiries take her to Brighton where Captain Fraser is staying. But then a girl's body is found on Hove Beach and Isabel is drawn into a shocking murder investigation.