If the Hog’s Head Inn was considered by many to be only slightly disreputable, then The Dirty Sack was the ultimate hole-in-the-wall (and under it as well.) The only nice thing said about it was that it was mobile. It was a simple matter for the owner to pull up stakes and move to another location when the local patrol came sniffing about or if the Headmaster of Hogwarts received too many complaints about drunken teenagers. Practically, the only way to find it was to know how to read the hints left engraved into the last known location.