The song was written in three hours, the day after her breakup. Adele arrived at the studio upset and wanted to write a sad, wounded ballad. Paul Epworth pushed her in another direction. He persuaded her not to stay inside something sorrowful and resigned, but to write something harder, fiercer, more forceful. She has openly credited him for that, and also for pulling vocal things out of her that she did not even know she could reach.