Worth it for the backstory alone, this product opens with a dire tale of how a greedy and intolerant emperor who confused dire poverty caused by crop failure with a mere unwillingness to pay taxes was eventually deposed... but not before he'd both devastated the township that was the centre of what he perceived as rebellion and had built a gaol there. That emperor's long gone, but the gaol remains...
There is a description and a rough sketch map of this dire establishment, a strange place indeed that's built on a towering column and hangs out high above the surrounding wasteland (a cell with a view, perhaps?). If you indend much running around therein, you may need to come up with more detailed maps, especially if you use miniatures for combat, but the sketch and description are enough to give a feel for the place.
Several people are then introduced: the warden, a guard,and a couple of prisoners; each with a whole backstory of their own. Then comes several plot outlines involving the gaol. Perhaps the party is hired to get someone out of there, whether wrongfully imprisoned or in need of incarceration but with friends wealthy enough to hire folks to break them out. Or the characters might even have fallen foul of someone and been imprisoned. Or... there is plenty of food for thought here with twists and turns aplenty to make a full-blown adventure.
A couple of interesting items, a few rumours and some encounters wind this up. Perhaps worth tucking aside for when your characters annoy you so much that they need banging up... but certainly an interesting location to place in some out-of-the-way part of your campaign world just ready for when you need it.