As he opened public impeachment proceedings last week, Representative Adam Schiff invoked Watergate—which, after all, ended well for Democrats. To understand how that history applies, or doesn’t, to the current proceedings, The New Yorker’s Dorothy Wickenden spoke with Thomas Mallon, the author of the deeply researched “Watergate: A Novel,” and of historical fictions about Ronald Reagan and George W. Bush. How would Mallon write the story of the Trump impeachment as a novel? “I would go right inside the heads of Lindsey Graham, Ben Sasse, and Mitt Romney,” he tells Wickenden. “A guilty conscience is one of the best springboards for fiction.” Plus, a conversation with Philip Pullman, whose beloved trilogy, “His Dark Materials,” has been adapted for a new HBO series. But he’s already onto a second trilogy about its heroine, Lyra, because he has more to learn about her universe.