“Martin will roll his eyes at me, but I always feel I have to include the first time I heard about him in our origin story,” Ms. Greenhouse said.

Mr. Mulkeen and Ms. Meier-Zimbler attended a 2010 holiday party in Park Slope, Brooklyn. “I had just gotten out of a serious relationship, and he seemed really nice,” Ms. Meier-Zimbler recalled. She didn’t expect to meet anyone — or even go to a party — that night. Instead, she was planning to pick up Ms. Greenhouse at the airport. After a year and a half of working as an editorial assistant in London at the literary magazine Granta, Ms. Greenhouse was returning to New York.

“I had been dating this British guy and we broke up, and my grandfather was dying,” Ms. Greenhouse said of her decision to move back to New York. “I had always feared the rat race of New York, but my family is here.” She also had a job interview lined up with Robert Silvers, the longtime editor of The New York Review of Books who died this year.