COED says this:
burglar
". noun a person who commits burglary.
— ORIGIN from Old French burgier ‘pillage’."
It is a connection between borough and burglar, both through Old English and Old french.From bhergh to borough to burglar. Were we not trying to find where the thief came into the story? Wasn't that Zed's question?

Devil's mountain maybe isn't smooth enough to be a monadnock.
Imposing, all mountains are imposing.