In 1930s mysteries, all sorts of motives were credible which aren't credible today, especially motives of preventing guilty sexual secrets from coming out. Nowadays, people sell their guilty sexual secrets.
The world of the terminally ill is the world of neither the living nor the dead. I have watched others since I watched my father, and always with a sense of their strangeness. They sit and speak, and are spoken to, and listen, and even smile, but in spirit they have already moved away from us and there is no way we can enter their shadowy no-man’s-land.
A picnic may well be a metaphor for life. The essentials for happiness are the right company, moderate if sanguine expectations and a reasonable standard of physical sustenance and comfort, the whole being bedeviled by the belief that there is always something better to be had if only one presses on.
I love the idea of bringing order out of disorder which is what the mystery is about. I like the way in which it affirms the sanity of human life and exorcises irrational guilts.
It's possible to fight intolerance, stupidity and fanaticism when they come separately. When you get all three together it's probably wiser to get out, if only to preserve your sanity.