Even though they're on friendly terms, Piper is irritated being around Nora so much; she often threatens to kill Nora, but in a joking way, she swears.
Piper is called to the courthouse, and an Assistant U.S. Attorney explains that she is in no legal risk as long as she doesn't perjure herself, which she doesn't plan on doing.
Back in the Chicago MCC (Metropolitan Correctional Center) Piper actually misses Danbury—to be clear, this is like eating at Arby's and missing McDonald's.
But Larry comes to visit, even though Piper is all the way in Chicago, and they have a recreation area on the roof that one of the officers takes the inmates up to later.
The trial happens. Piper testifies. After, she makes a request for "a good cup of coffee" (18.70) and is presented with a steaming-hot cup of Dunkin Donuts. Um, she said a good cup of coffee. (Sorry, East Coasters—Philz FTW!)
The Jansen sisters are sent back to their prison, but Piper is still held in Chicago.
In fact, she's released from there.
Larry has to drive all the way back to get her, but he does, so when Piper is dumped out of the prison, there he is. She runs toward him: "No one could stop me" (18.122).