Last Wednesday night at the Waverly Inn, Josh Duboff stepped out of his own book party and onto the sidewalk—not for a cigarette with the surprisingly large clutch of smokers outside but for some fresh air. He did this several times as the crowd inside the warm, narrow garden room grew larger, younger, and drunker.

“I mean, it seems like everyone here is in their early 30s,” said one guest, in her cups and pleased with her play on the title of Duboff’s debut novel, Early Thirties, which was published the day before the party. The book follows two best friends, Victor and Zoey, as they navigate the challenges of adulthood in New York City and try to avoid what seems to be inevitable: drifting apart.

One of the first guests to greet Duboff was his best friend, Alyssa Reeder, co-founder of Kaia Gerber’s book club, Library Science. (Some partiers whispered about whether she had been the inspiration for Zoey, though Duboff has remained coy about exactly how autobiographical his book is.)

“It’s a bit of a media-world fever dream. Every person we ever gossiped about in the elevator or avoided in the cafeteria is in this room,” said Reeder.

After an hour, the crowd—which comprised the likes of chef Alison Roman, writer Hunter Harris, WSJ Magazine editor Sarah Ball, Wall Street Journal reporter Lane Florsheim, the Infatuation C.E.O. Paul Needham, Parcelle founder Grant Reynolds, and The Drift co-editor Kiara Barrow—began to blur together, and more veteran editors and writers such as Michael Hainey, Aimée Bell, David Kamp, Evgenia Peretz, and Bruce Handy realized they were being overtaken by millennials and Zoomers, and made their way to the exit.

I asked Duboff how Victor and Zoey would fare in such a scene: “Victor would probably say something in a conversation with an acquaintance that he immediately regretted but that the acquaintance didn’t even register, and then text Zoey to ask if it was O.K. Zoey would respond, ‘It’s fine, Victor,’ without even reading the text.”

When Zero Bond founder Scott Sartiano arrived at 8:15 p.m., last call had already been announced. Luckily for him, nobody was ready for the party to end. Like a character out of his own book, Duboff proclaimed, “Corner Bistro for burgers!”

Carolina de Armas is a Junior Editor at Air Mail