What on earth are Little Dorrit and Maggy doing at Arthur's house at midnight?
Turns out they were watching Fanny perform (without Fanny's knowledge – basically, Little Dorrit was checking up on her) and got locked out of the Marshalsea. Little Dorrit told her dad she was going to a party.
Arthur is horrified by how thin her clothes are considering it's a cold fall night.
As she is warming by the fire, Little Dorrit thanks Arthur in a roundabout way for getting Tip out of prison.
Then she tells him that Flintwinch has been watching her comings and goings.
Finally she asks him to not give Dorrit money anymore, even if he starts asking for it. She doesn't want Arthur to only see Dorrit as a guy who degrades himself.
There's a whole lot of denial going on, though, as Little Dorrit tells Arthur that she is super-proud of her dad.
Finally, Little Dorrit and Maggy get up to leave. They tell Arthur they're going to Maggy's, and Arthur doesn't realize that they could end up homeless for the night.
End up homeless they do, since they can't wake up the people from whom Maggy rents a room (and she apparently doesn't have a key).
They are forced to wander around the shady parts of London all night long, since sleeping on the street would be too dangerous.
There are beggars, drunks, people fighting, and even a prostitute. It's really not a good scene.
In the early morning, after a long night, Little Dorrit sees a light on in a church and goes in.
It's the church closest to the Marshalsea, the one where her own baptism was recorded. The sexton there recognizes her and sets up a makeshift bed for her and Maggy in front of a fire.
He gives Little Dorrit the burial volume of the church registry to use as a pillow. Nice.
And then, as if we weren't feeling bad enough, the narrator piles it on: "This was Little Dorrit's party. The shame, desertion, wretchedness, and exposure of the great capital; the wet, the cold, the slow hours, and the swift clouds of the dismal night. This was the party from which Little Dorrit went home, jaded, in the first grey mist of a rainy morning" (1.14.122).