In a battle between good and evil this epic, not everyone would make it through alive—that would have led to “very fluffy, cozy books,” she told Meredith Vieira. “You know, suddenly I [would be] halfway through Goblet of Fire and suddenly everyone would just have a really great life and … the plot would go AWOL.”

Which is not to say that Rowling knew exactly who was on the chopping block. She thought about killing Arthur Weasley after he’s attacked by Nagini in Order of the Phoenix, but instead opted to save him, partly because “there were very few good fathers in the book. In fact, you could make a very good case for Arthur Weasley being the only good father in the whole series.” (She also “seriously considered” killing Ron, then thought better of it.)

Instead, Lupin—a character she had no intention of killing when she began the books—and Tonks died during the final Battle of Hogwarts. “I wanted there to be an echo of what happened to Harry just to show the absolute evil of what Voldemort's doing,” she said. “I think one of the most devastating things about war is the children left behind. As happened in the first war when Harry's left behind, I wanted us to see another child left behind. And it made it very poignant that it was [Lupin and Tonks's] newborn son.”