INTRODUCTION Who knew Nora Ephron was such a Harpy? Barbara Walters, that''s who. Following Ephron''s death in June 2012, the New York Post reported that she and Walters were members of the Harpies, described as "a close-knit cadre of lunching ladies who''ve met to eat and argue over twelve years at Michael''s, the Four Seasons, and ''21.''" The Harpies include other media moguls too, and according to my favorite tabloid, the ladies often gossip about Hillary--her whereabouts, her fatigue, her hair--and engage in "intense debate" over the latest headlines. "God forbid you were wrong," a Harpy insider told the Post, "or you were dismissed and reduced to rubble . with great affection." It seemed that these women were exacting and precise, that they held themselves and each other to high standards, and that they pushed and challenged their friends. But they did it with humor and ultimate kindness. I was approaching my book deadline when I read about the Harpies at the breakfast table.

"See?" I jumped up and cheered. "All the girls are doing it! It''s sweeping the nation!" As a cabal of bold-faced names, the Harpies are pretty swank in their own right. They''re movers and shakers, no doubt. But, I won- dered aloud, do they know they''re part of something bigger? Do they know that their group and others just like it are changing the world? My three sons rolled their eyes. They raced out the door to their all-boys school. I didn''t plan to write a book at this very moment in my life, but it''s my family''s consensus that with all the testosterone at home, I needed to talk to some girls. And once I started interviewing dynamic, motivated women, I found I couldn''t stop. I didn''t know exactly what was happening, but I knew it was important.

At the beginning, it was a gut feeling, a notion that I had unearthed something meaningful that was shaping women''s lives. But I didn''t yet realize how important it would be for me personally. I didn''t know I''d end up living this story as I was writing it, that it would be the story that changed my life. But more on that later. It all started at a women''s conference in California. There, I met one female senior executive who introduced me to another and then another, and each one was fascinating and charismatic, en- gaging and kind, vulnerable and bold. They didn''t carp about "balance" or lament not "having it all." They didn''t feel oppressed and under siege, and their days weren''t some dismal, tough slog.

They took evident joy in both work and personal life, adoring jobs and families alike. "Why don''t we ever see anything about women having fun at work?" one woman asked. "Sure, there are battles, but I work so hard and I love it. Can''t we ever accentuate the joys over the battles?" While it''s not PC to say this, these ladies were also cute. I liked their outfits. They had chic shoes and healthy hair. Here were women comfortable in their own skin, not trying to dress and act and sound like guys. Here were the opposite of hoary archetypes-- those sharp-elbowed, steamrolling, ball-busting bitches.

And here was an antidote to the dreary navel-gazing and hairy-legged petu- lance of Women''s Studies 101. These chicks were successful, but still really fun. So what was their secret? I started listening and learning, observing how they made it all work. And before long, they were gushing about their girlfriends. Professional women from their twenties to their seventies started recounting hilarious stories, and often they''d begin like this: "Well, in my dinner group." "Your dinner group?" I''d ask. "Who''s in your dinner group? What do you do when you get together?" Eat, naturally. Drink, copiously.

And gossip, naughtily. It all sounded like a blast. I started to discover dinner groups and salons and coworking and networking circles in major cities across the United States. In almost every case, the women thought they were alone in assem- bling clusters of dear, smart girlfriends who met regularly to learn and share. They''d never heard of the other groups, and when I told them they were thrilled. "You''re onto something," they''d say, and then introduce me to their pals. At that point, I didn''t have a thesis or a commissioned article or a book contract. All I had was a hunch.

Yet accomplished, in- demand women agreed to talk to me. They made themselves avail- able for open-ended interviews that, for all they knew, might go nowhere--just because a friend had asked them to. So many times in the course of reporting, I heard, "I never talk to the press. I''m only talking to you because so-and-so said to." The ladies were busy, but not too busy to do a favor for a friend.