Archie Freeman was a man who resided inside Arkham City, despite the rampant criminality therein.
While searching for food in a dumpster, Archie happened upon the body of Batman - badly wounded after escaping a battle with Bane. He brought Batman back to his apartment and helped him recover from his injuries. He explained something of his history - that he used to be an usher at the Monarch Theatre. He and his wife Alice lived together in that apartment until she died but Archie elected to stay, even when his building became part of the Arkham City mega-prison.
A couple of thugs would regularly come and extort Archie for money and valuables but even injured, Batman intimidated them into leaving the entire building alone.
After they left, Batman had Archie tell him stories of Gotham from Archie's youth.