Work Text:
Mrs Hudson sees many visitors to 221B. To her front door come knocking those of high society, or wanting to be. Perhaps they hide their faces or come at night, if they fear reprisal or scandal, but the front door is their due.
To her back door comes the other side of society. She lets them in, she lets them wait, and she lets them up just the same. Some she sends away, for the man they're visiting isn't there, and they must await his return.
Occasionally they are the man they've come to see. She's become used to that.