Simon Cowell

Throughout his nine-year reign atop American Idol, Simon Cowell reveled in his rep as reality TV's harshest judge. But in person, he's all about being zen. Just ask Idol expert Richard Rushfield, author of the new tell-all, American Idol: The Untold Story.

"We met at his huge office at Sony in London, which was two enormous rooms with lit candles, ginger tea and crutatae. He was very open. He wanted to know all the dirt I had heard about him. He did not respond defensively at all when I told him some of the unpleasant things that were in the book," Rushfield tells TVGuide.com."I think because he was so honest, there's a much more complete portrait of him in this book."

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As Idol prepares to celebrate its tenth anniversary and usher in a new judges table (among many other changes), Rushfield has compiled nine seasons of backstage dirt for the book (in stores Tuesday), including interviews with everyone from Cowell to creator Simon Fuller and topics ranging from widely rumored voting controversies (i.e. Jennifer Hudson's early exit). He's even got the scoop on secret tensions between the contestants and the judges that will even shock some of the show's most ardent followers.

But Rushfield says nothing compares to that first season, when Idol rose out of a slow summer schedule to eventually grab 22.8 million viewers for the season finale. There were also the fights and romances you didn't see!

"You just had a really interesting bunch of people. There were major fights backstage including one that came to a fistfight between two girls. On this season, another contestant had an enormous fight backstage with Simon Cowell where she called him a 'perv' to his face," Rushfield says. "You have a love triangle and people struggling to come out of the closet and deal with that. And you have the judges finding their way with each other, and Randy [Jackson] and Simon almost getting in a fistfight."

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You'll have to read to figure out who's smacking or smooching who.

Looking forward to Season 10 and the addition of Steven Tyler and Jennifer Lopez, Rushfield says it remains to be seen what the show will become without Simon. "With Simon leaving and with all the changes in the last year, it just really felt like this is the ending of the first Idol era. Now it's going to change and be something else, he says. "Instead of a Paula and a Simon, it will be three Paulas and that's going to make for a very different kind of dynamic. Whether it supplies enough drama, we'll just have to see."

If there's one thing that Rushfield has learned about America's search for the next superstar, it's to expect the unexpected. "There's the saying, 'We make plans and God laughs,'" he says. "Idol makes plans and the audience laughs."