On very short notice, Andy is given the nearly-impossible task of getting an advance copy of the unreleased seventh Harry Potter book for Miranda's twin daughters. Miranda, who is displeased with Andy at the time, seems to have done this in order to punish Andy, and is probably trying to make her quit. To Miranda's surprise, Andy manages to track down a copy of the manuscript and returns to the office victorious.
On top of that, she managed to get two extra copies to Miranda's twin daughters on the train. Without Miranda's knowledge.
In an early scene, after Andy snickers at something said during a meeting, Miranda proceeds to lay a verbal smackdown on her, during which she dissects her character and details the impact of the fashion industry to make the point that Andy shouldn't consider herself above fashion.
Andy finally gets fed-up with Miranda's demanding ways when she not only blasts her for something that wasn't her responsibility—the twins' passports expiring—she expects her to pull off the impossible task of getting them renewed within a matter of hours in the middle of the night. Andy tells her "Fuck you, Miranda. Fuck you", and walks away.