“I want to make people laugh. I want to create a show,” Rainbow Rowell read from her new novel “Landline” at a packed Harvard Book Store talk on September 19. She was quoting Georgie McCool, the novel’s television screenwriter protagonist, whom she mimicked by creating a show of her own, a show where she was the undoubted star. Flashback to 30 minutes earlier: a line had started forming outside the Brattle Theatre even though the talk did not start for an hour, and the Rowell fans already had their tickets. People angling for standby tickets in a different line stared ahead with greedy eyes and waited eagerly for their superstar.

Rowell sauntered on stage before her cue, deeming the HBS spokeswoman’s introduction short but good, and the audience erupted with laughter. Rocking red high-heeled booties—the very first heels she has worn since spraining an ankle in Scotland a few months ago—she strutted with confidence and launched into discussing “Landline.” Georgie and her husband, Neal, do not have a bad marriage, she said. They have two kids and routine lives in Los Angeles; they’re just tired. And the book features a yellow rotary phone that allows Georgie to communicate with her past. “There’s a magic phone in the book. It’s a magic phone, you just gotta move on,” Rowell said.

Rowell dove into a passage from “Landline,” but her reading quickly became a stand-up comedy act, ringing with truth, heart and a whole lot of jokes. Rowell, in fact, didn’t simply read to the audience members; she laughed and paused so they could absorb her enthusiasm and add to that laughter. The “reading” shifted into a conversation as she interspersed her own commentary with the text and brought the house down. When reading a sexually charged sentence in which Neal and Georgie share their feelings about wanting each other, Rowell added snarky sidenotes. “I like to write the romantic, guys,” she said. “George Clooney plays this part.” She followed this one-liner up with self-deprecating humor. “I wrote this scene so nothing really happens. But I feel like those efforts indicate a lot of passion.”

Rowell herself embodies that passion, a spark which first brought her from the world of news and column writing to fiction. Getting started is the hard part, she said. “Once you’ve written a novel, you know you can write a novel.” Rowell likened taking that first step to an episode from the “Little House on the Prairie” television series, a reference she feared would date her even though the Brattle crowd was on the older side. In the “Little House” scene, Mary and her husband must cross a river, and the journey seems so daunting that the producers had to cut the episode in two. “The first time you’re writing a novel, you’re crossing a river,” Rowell said. “When you have a novel completed, you’re confident you can do it.” Rowell is living proof of this statement. It took four years for her to write her first novel, “Attachments”; she wrote her second, “Eleanor & Park,” in three months. According to Rowell, however, the difference between writing “Attachments,” an adult novel, and “Eleanor & Park,” a young adult novel did not lie in the sub-genre distinctions. When Rowell sits down to write, regardless of the setting, she tries to jump into the heads of her characters and access their thoughts and how they would speak.

When Rowell wrote “Eleanor & Park” for a publisher in the United Kingdom, however, she assumed the team would market it as adult fiction. In fact, the book was pitched only to adult editors in the United States. Before deciding to crossover into young adult fiction, Rowell and her team discussed the book’s cover and its ’80s references, which had the potential to be lost on younger readers. But Rowell knew the cultural references would not make or break the book’s accessibility. With her characteristic sass, she reflected on her own YA reading experiences. “When I was a teen reading ‘Little Women,’ I wasn’t thinking, ‘Why are they lighting all of these candles?’” Rowell said. “When I was a teen I was a much more ambitious reader. Now I read half ‘Sherlock’ fan fiction and half my favorite authors, not Joyce.”