The recipient of four starred reviews, Kristin Cashore’s third novel, Bitterblue, hit bookstores May 1 and hit the New York Times bestseller list (at #2) two weeks later. The Times reviewer called it “thrillingly imagined and beautifully executed.”

“I read that sentence over a couple of times,” Cashore admits.

She has earned a moment to savor praise, because birthing Bitterblue was all struggle. The first draft took nearly three years.

“She was writing all the time,” says Cashore’s editor, Kathy Dawson, associate publisher and editorial director for fiction at Dial. “She took the manuscript with her everywhere she went. But when I would check in with her, she’d be unsure if what she’d written was really a book. I remember she told me, ‘Well, I think I’m a third of the way done and I’m on page 300.’ ”

When the first draft – a whopping 800 pages long – thudded onto Dawson’s desk in the fall of 2010, the veteran editor was unsure of what to expect. Dawson, whose reputation as a skillful but demanding editor is backed up by having shepherded Printz, Newbery, and National Book Award finalists to publication, fortified her resolve with a reminder that she was “not in this business to make friends.” She wrote Cashore an editorial letter which suggested in the most diplomatic way possible that she cut at least 300 pages – and start from scratch.

“I was terrified” to send it, Dawson recalls.

“Not possible,” was Cashore’s first reaction. “I definitely had a little meltdown.”

There was no track record for this. Dawson had edited both Cashore’s debut novel, Graceling, and its follow-up, Fire. Both manuscripts arrived in very good shape. “Mostly what I did was line editing and suggest she add a scene here and there.”

Following receipt of the letter, the editor and author spoke on the telephone. Dawson told Cashore she had started a “chapter map” for Bitterblue, a document she creates for every book she edits, which she uses to test whether a chapter is doing enough. “These are down and dirty notes for me so I can make sure each chapter has a reason to exist,” Dawson says. “I keep track of plot developments and reveals. There’s got to be a reversal or a transformation in each chapter, otherwise it’s not really a chapter.”

Though Dawson had never shared her chapter map with an author before, she and Cashore were meeting the following week at NCTE in Orlando, where Cashore was receiving the Amelia Elizabeth Walden Award from ALAN for Fire. Dawson agreed to pack the chapter map in her luggage.

Bitterblue’s extreme makeover, then, began in (of all places) Disney World. Dawson and Cashore talked and walked around their hotel grounds for a while before settling in on poolside chaise lounges, dwarfed by a fake yacht.

Dawson had small suggestions – aging Bitterblue up from 16 to 18 because an “unexpected vibe” with one character looked as though it might lead to a sexual relationship; toning down Katsa and Po’s “graces,” so Bitterblue didn’t seem so ordinary in comparison.

But she had far bigger concerns with the overall arc of the story. “I asked Kristin, ‘What is this story really about?’ and, at that point, she wasn’t sure.” Certainly, all three of Cashore’s books are about a lot of things – they are romances, fantasies, adventures full of pitched battle and political intrigue. They also aren’t sequels. Even coming up with an umbrella title for the series has been tough. “My favorite suggestion was ‘Horrible Father Figures and the Women Who Kill Them,’ ” Dawson said.

(Cashore insists the next sentence in this story must be: “Please tell everyone I have the sweetest, kindest, gentlest father in the world.”)

Bitterblue didn’t necessarily have to follow any one particular thread, since Cashore had successfully woven so many into her previous books. But, Dawson insisted, it had to be about something.

“To me, this book was very much about recovering from grief. [The whole kingdom] literally needed to discover another language before they could comprehend the grief,” Dawson says. “But I’m not necessarily right about that. I’m just trying to get the author to look at the right stuff, to get her to see what’s on the page and what isn’t there yet.”

Cashore looked. And listened. She went home with Dawson’s chapter map, which eventually grew to 37 pages. She put the first draft away, and started from scratch.

“It was the most important, productive thing she ever said to me. It was almost like a psychological trick. It lifted me out of the mire and gave me an approach that worked,” Cashore said.

The next draft was 500-something pages, Dawson says, “and just like the first drafts for the first two books.” Line edits and a few tweaks.

Friends and family told Cashore, who affixed to her office wall words made out of wrapping paper and fabric swatches that read, “A Book Takes a Long Time,” that she had earned a vacation. Instead, in four months, she wrote a contemporary realistic YA novel that she’s already shipped off to her agent, Faye Bender.

“After Bitterblue, I had all this adrenaline and I had this confidence that pushed me,” Cashore said. “So rarely do I feel like that as a writer that I had to take advantage of it.”

Bitterblue. Kristin Cashore. Dial, $19.99 May 978-0-8037-3473-9