A couple of weird things happened in Markarth, one of which is probably a glitch but I'm not sure about the other. First thing(glitch) Arnlief store closed so waited..and waited..and after 24 in game hours still closed so I took my custom elsewhere. The second thing is; Ghorza the blacksmith has disappeared!! I've been to Markarth umpteen times with various characters and this has never happened before. I don't think its a glitch as Tacitus has dialogue stating that he has taken over and he is buying and selling gear ! So where is Ghorza?? Anybody know?

If the apprentice has taken over, then Ghorza is dead. For the locked store, sometimes you have to unlock the door for the stupid shopkeeper that has locked themselves in.

LOL i didnt know shopkeepers could lock themselves in?!

Did you undertake the Cidhna mine quest and side with the Forsworn? It's very likely that NPCs get killed while they're escaping through the city.

Some NPCs may also be affected by Namira's daedric quest, although the blacksmith isn't one of them.

Just be prepared if she starts telling you you are tresspassing.