My memories of Halloween include trying to find a costume that looks good over a winter coat and books. I remember being able to wander blocks with no adult supervision and coming home with a bag so full of stuff that I almost had to drag it. Now, my grandfather, born in 18908, remembered Halloween as a great chance to tip over outhouses, steal tables and chairs from porches for the bonfire and generally commit vandalism. He was quite wistful telling me about it and insisted that modern kids had no gumption.
It's still a great time to set a mystery. Are there any Halloween anthologies? I know there are lots for Christmas but I can't think of any collections of mystery stories for the spookiest night of the year.
I could write one about the holy water font in Rennes-le-Chateau. It is supposed to be a sign that the priest who built the chapel really worshipped devils. What you can't see is that the devil is being held down by three angels standing on the font. Interesting how images, both visual and literary, can be distorted. I didn't get a picture of the angels but I'm going back this Christmas and will get that, too. They aren't as interesting at Satan, I'm sorry to say.