Skeleton Key — Lenore Glen Offord

Georgine Wyeth is a young widow keeping house for herself and her young daughter, and paying the rent by typing for a local academic, a scientific gentleman. Working late one night (there's a war on, you know), she gets caught in a blackout, only to trip over the dying air-raid warden. A simple snatch-and-grab gone wrong? Or something more sinister? And could Georgine's work for that scientific gentleman have put her in jeopardy?