August 9 is D-Day for Hollywood’s ten-percenters, the classic industry terminology for agents.

That’s when James Andrew Miller’s “Powerhouse: The Untold Story of Hollywood’s Creative Artists Agency” hits shelves, promising to pull back the curtain on one of the most secretive and influential talent agencies in the entertainment business. It’s probably the most hotly anticipated book since Julia Phillips’ tell-all “You’ll Never Eat Lunch in This Town Again” dropped more than two decades ago.

Details that Miller unearthed about CAA’s transformation from an also-ran industry into a titular powerhouse are being closely guarded, but the rumor mill is already churning, and some of the town’s biggest figures are on edge.

The book took three years to complete, and involved countless interviews with the likes of Michael Ovitz and his fellow super-agents Ron Meyer, Bill Haber, and David “Doc” O’Connor. Just as he did in “Live From New York” and “Those Guys Have All the Fun” — his previous explorations of “Saturday Night Live” and ESPN — Miller employs an oral history format, allowing the men and women who rewrote the rules of talent representation to dish about their feuds, triumphs, and years in the trenches. Variety spoke with Miller on the eve of the book’s publication to get his thoughts on how CAA revolutionized the entertainment landscape and the challenges that the agency world now faces.

Michael Koelsch for Variety

After tackling ESPN and SNL, why were you interested in this particular acronym?
With SNL or ESPN, everyone knows what those initials mean, but one of the great challenges of this book is that someone in Kansas doesn’t understand what CAA’s initials stand for. I wanted to make them understand why they should care. It’s much more a part of their life; whether they’re eating at Chipotle, watching Jimmy Fallon, or listening to Katy Perry on the radio, CAA plays a part in all of that. At the same time, CAA is very, very private, and somewhat Kremlin-esque, so the idea of getting inside there intrigued me. A lot of the agents I spoke to had never really spoken with journalists before, or at least not on the record.

How did CAA change the agency business?
They got rid of silos. The world of William Morris and others in the ’60s and ’70s was hierarchical and regimented. Everyone worked in their own little fiefdoms, and there wasn’t a great flow of information between departments or between colleagues. There was a pseudo-aristocracy to it all. CAA made sure that all of the information they had was transparent and accessible to all of its employees. If a client said no to a particular role at a particular studio, they were able to say he doesn’t want it, but we have three other people available. They became about providing solutions, not just talking about problems.

There just was — this sounds banal — drive and competitiveness and relentlessness woven into the fabric. Other agencies seemed moribund in comparison. At CAA, you had people who were hungrier and unrelenting. They were very disruptive.

Weren’t they innovative in the way they packaged movies — filling them with director, writer, and acting clients?
They didn’t invent packaging, but they became known for it in a way that was unparalleled. One of the things that they did was put a lot of value on writers. When scripts came in, there was no way certain elements were going to be given to another agency. There were countless big projects beginning in the early ’80s where you’d look and think, “Wow, every important spot has a CAA client on it.” It got to the point where they were casting movies out of CAA. Can you imagine being another agency and having to send your client over there to read for the director? And you just know they’re going to be treated like kings and queens when they get there.

Michael Ovitz has had a dramatic fall from power. Has that changed him?
It’s very complex. Viewing him now versus if I had done the book 15 or 20 years ago, it would have been a very different Michael Ovitz. He doesn’t pull many punches. He’s very blunt in the book. He’s had a lot of time to reflect on what happened. He’s also at a stage in life where he’s a grandfather now, and certain things don’t matter as much to him anymore.

He was a dependent variable in the equation. He was such a big part of CAA, and in many ways beyond that fact he used to be called the most powerful person in Hollywood. He transformed the traditional agency business.

If Ovitz was the face of CAA, what role did Ron Meyer play?
Michael Ovitz took up a lot of oxygen and got a lot of notice as head of CAA, but Ron was an essential piece of the puzzle. They complemented each other. They had few qualities that overlapped. Ron did not wake up in the morning wanting to fly out and conquer Japan and be a consultant on a massive deal with Matsushita. And Mike did not get up and think, “How can I make Jessica Lange’s day better?” Almost without designing it, they divided the world of CAA.

As Ovitz fell, Meyer continued to rise. He’s now vice chairman at NBCUniversal, having survived multiple changes in corporate owners. What’s the key to his longevity?
He has low levels of ego and paranoia. That’s one of the reasons why he was a good agent and so many clients remain devoted to him. Through all the owners at Universal, he’s been like Switzerland. He has an ability to care about people and careers in a way that’s very self-effacing. He’s generous with his time, and he’s a great mentor to people. In a town famous for people behaving badly, Ron is very good to people, and also incredibly honest about his own fallibilities.

How has the agency world changed?
It’s more of a buyer’s market than seller’s market. In the old days, Ovitz could say I’ve got a great script, a great director, and two stars — let’s go make a movie. Today it takes a lot more than that. Even the perfect script and a big director aren’t enough to get financing all the time.

What have agencies done to adapt?
At some point, it dawned on them that the movie and television business is changing, and if they were going to continue to grow and expand and really be an important part of the content world, they were going to have to get into other businesses and find new revenue streams. CAA started CAA Sports about 10 years ago, and now it makes more money than their movie or television divisions. Ovitz started CAA’s marketing and consulting division, and they stepped away from that, but then they got back in. That’s the judo move — to not be wedded to what’s going on with the studios. There was also this marriage with private equity, be it CAA with TPG, or WME and Silver Lake. That’s allowed them to get involved in a host of other businesses that they never were able to get involved in.

Doesn’t that come with risks?
Definitely. The big risk is that you’re no longer the lord of the manor. You’re reporting to somebody else now.