Jack Pumpkinhead and Jellia Jamb went up the hill to fetch some water. That's their story and they're sticking to it. They won't say what happened up there, but Jack fell down and Jellia came tumbling after. Jellia is fine. Jack seemed a little shaken up, according to the Scarecrow, and needed his head replaced, but he'll be OK. Seems like everything turned out fine. So why can't I stop thinking about it? I've been many things in my time; General, queen, farmer, painter... I guess now I'll add detective to the list.
The first thing that doesn't make sense is, what business brought the pumpkin farmer and the palace maid together? The story about fetching water is an obvious fiction. Jamb lives in the palace and has ready access to running water. Pumpkinhead doesn't even live in Emerald City at all, and must have access to water on his farm. You can't grow pumpkins without it. Or anything else for that matter. I know they met once before, back in the days of Scarecrow's rule but, could it really be connected? They do say that water kills witches.
If Mombi somehow got her powers back, that would mean she'd found a way around Glinda's magic. I'm not scared of much (other than mice) but that frightens me. You can't always rely on a plucky human child to show up and solve your witch problems. That could probably only happen once or twice, realistically. And anyway, Dorothy's too soft.
Ozma never had the stomach for violence either, so Jellia couldn't let her find out what they had planned. Jack must have lost his nerve, and Jellia couldn't take the risk that he'd go running to mommy to confess. Once the witch is dealt with, down goes Jack and splat goes the pumpkin. Perhaps it's for the best though. The witch is dealt with, Jack's gone home to Winkie Country, and Ozma's none the wiser. It never sat well with me that Mombi got off so easily the first time. Best to let sleeping dogs lie.
Jack and Jill went up a hill, to douse a witch with water
Jill killed Jack dead and broke his head, so he couldn't tell his mother
Jack went home, a new head he'd grown, his memories aflutter
Now Mombi's gone, we'll all move on, and won't have any bother