Frost heave

A couple of days ago, my neighbour and I found this at the base of a tree we were cutting dead wood out of. The tree overhangs both our properties, but this was in the grass at the base of his side of the tree.

I just heard from a previous owner, who sold the house about ten years ago, that her real estate agent had buried it there when buyer interest was low in their house. And the house did sell.

It is Joseph, by the way, the carpenter, and modern folklore (starting in the USA about forty years ago) is that burying him upside-down will help sell the property he is buried on. Who am I to question it?

I expect the frost heaved him up but left his head below somewhere.