Halloween used to be a Pagan holiday in which the Celts celebrated by creating a bonfire, and wearing masks and outfits to scare away the spirits of the dead or malevolent spirits. Also, I think there were some sort of ritual sacrifices but I am not certain on that. Nowadays.. it's pretty much a far cry from what it used to be. Children dress up in costumes, and go from door to door to get treats and candy.
"Ahhhh, I see. Then it’s something of a festive holiday. That makes sense."
"This Halloween thing sounds like it could be fun, sis! Think I could try it?"
"Of course. I don’t see why not. It sounds like a pretty harmless enough festivity, so I think you’ll be alright."
"Alright, cool beans! Thanks, sis!"