Merdle has a farewell dinner for Dorrit, after which he walks him out to his carriage. This is high honor.
Dorrit says good-bye to Fanny, praises her awesomeness, and wishes that Amy were more like her sister.
As Dorrit goes back to his hotel, he sees Young John Chivery waiting for him. (Remember him? The kid from the prison who was in love with Little Dorrit.) The servants say that Chivery claims to know Dorrit and that he wants to see him.
Dorrit calmly asks him upstairs, closes the door, and then... scares the living daylights out of him by grabbing his lapel and demanding to know what he's doing there.
Poor John holds out some cigars, like in the old days, and Dorrit loses it even more.
Then, seeing John's horrified face, Dorrit calms down, cries a little bit, and tries to smooth things over.
John really just wanted to say hello and ask how Amy is. Without any kind of ulterior motives or anything – as he says, "in my poor way, I am too proud to" have any kind of secret meaning (2.18.30).
Now Dorrit feels terrible and apologizes, but John looks traumatized.
Dorrit asks about the Chiverys and also about the prisoners. Then he writes a check for them. As John is leaving, Dorrit listens at the door to make sure he's not going to tell anyone anything. Wow, paranoid much?
The next morning Dorrit starts off for Italy and the farther he gets from London the better he feels.
He starts daydreaming and imagining things.
In Paris he goes to a jeweler and asks to see something he could give a lady as a present. The saleswoman asks if he wants a love gift or an engagement gift. He thinks about it and decides to buy both.