During my 25 years as a magazine editor, my favorite part of the job has always been helping writers figure out what the story is: where to start it, where to end it, what’s important and new about it. So it was with no small amount of humility that, earlier this year, I sat in a Google corporate cafeteria along the West Side of Manhattan and watched as one of my longtime writers — Steven Johnson, the technology journalist and historian — received that kind of guidance from an A.I. instead of me.

Johnson, who has published popular histories about pirate attacks, the invention of modern policing and the birth of public health, had begun noodling on a possible book about the California gold rush of the mid-19th century, he explained. But he was still at the point where he didn’t know much more than that. “What’s my twist?” he said. “Literally, I don’t know.”

To figure it out, Johnson had loaded some of his sources into NotebookLM, an app for researchers and writers that he himself helped build, after becoming the editorial director of Google’s Labs division three years ago. Unlike most other A.I. tools, which draw their answers to questions from the mind-boggling infinitude of data they were trained on, NotebookLM draws only from files selected by the user, on the premise that most forms of research benefit from thoughtfully curating your source material.

Since the product’s worldwide release last year, Google and Johnson have been promoting its utility for all manner of tasks, whether it’s auto-generating minutes and takeaways from an audio recording of a meeting or encouraging a more licit use of A.I. among college students. NotebookLM’s most viral capability is an auto-generated podcast, which in a matter of a couple of minutes will spit out a detailed conversation between two freakishly realistic voices, drawing out the key concepts of the source material. But as an occasional author of history books myself, I was most interested in how A.I. — one of whose many superpowers is the ability to inhale large amounts of text in an instant and offer credible summaries of it — might transform the way history is written.

At Google that evening, as the sun went down over the Hudson, Johnson showed me the results of his experiments so far. He started his brainstorming process by giving NotebookLM excerpts from one of the finest existing histories on the Gold Rush, H.W. Brands’s “The Age of Gold.” He thought he might want to focus on the conflict between white gold-seekers and the Native American groups living in the Yosemite Valley in the 1850s, so he uploaded the text of an older source called “Discovery of the Yosemite,” by Lafayette Houghton Bunnell, who was part of the Mariposa Battalion, the militia unit that rode into the valley in 1851. Next, to bring in the Indigenous perspective, he went to public-domain websites and found two accounts about the people whom the battalion expelled from the valley: “The Ahwahneechees: A Story of the Yosemite Indians” and “Indians of the Yosemite Valley and Vicinity.”