How does a children's picture book happen? In the case of "Dark Emperor," quickly at first, then very slowly.

Here's how three Minnesotans collaborated on a book that's getting rave reviews for its poetry and illustrations. Ann Rider, an editor for Houghton-Mifflin who works out of Lutsen, was the matchmaker who leaped on Orono poet Joyce Sidman's impressions of a forest at night. Rider had long been taken by the playfulness in the work of Rick Allen, a printmaker in Duluth. Immediately, she knew this pairing could work.

Introductions were made, inspirations exchanged and, after almost three years, "Dark Emperor, and Other Poems of the Night" is ready for its ultimate collaborator: a reader who will give it a voice.

THE EDITOR

Much of Ann Rider's job as an editor for Houghton Mifflin is reading a lot of writing that never amounts to anything worth pursuing.

Or, as she was quick to add, anything that she -- Ann Rider -- should pursue.

"The least favorite part of my job is telling people no, turning people down," she said. "I always tell them it's so subjective. I generally know if I'm the right editor for something, or if it would be a disservice to take a project on."

There was no such deliberating when Joyce Sidman's collection of poems about animals that revel in the darkness appeared before her. She's worked with Sidman before, "and she has a pretty high batting average. She works really hard on every project she's involved in and this was very resolved."

Most intriguing, however, was "a sense of playfulness that isn't always in her work." Rider immediately knew that this may be the moment to tap Rick Allen, a Duluth illustrator who'd been on her radar for some time. "I needed someone who wouldn't take the night so completely seriously."

Rider said she always involves the author when determining the best artist for their words, and the fact that everyone involved is a Minnesotan had nothing to do with it. "That was just a nice bit of luck."

Picture books take a tremendous amount of time, yet even at two years in development, "Dark Emperor" moved along at a sprightly pace, she said.

Rider has worked in publishing since college, and had an immediate bond with children's literature. Now she works exclusively in that genre. "It's a rich field," she said.

About 20 years ago, she moved from the East Coast to Lutsen, where the ski resort is her family's business. Because she works with writers from all over, the remote location is as near as she needs to be to anyone.

Now her next goal is to find another project for Allen, but it's impossible to say when that will happen. "I have to wait for it to fall from the sky."

THE WRITER

Joyce Sidman says she used to be just the teensiest bit afraid of the dark. She liked the idea of nighttime, with its starry mysteriousness. But to actually be out there with no light? Creepy.

Still, the poet knew that many perfectly benign creatures prefer the night: raccoons and owls and tiny tangerine-bright newts called efts.

"To Know the Dark," a poem by Wendell Berry, prodded her thoughts. "What he said was that when you go out in the dark with a flashlight, you don't get to know the dark," Sidman said. "You have to do without any light."

And what's darker than a forest? The idea of a book about a forest had been percolating ever since "Song of the Waterboatman" was published in 2005. That collection of poems about a pond was followed the next year by "Butterfly Eyes," about a meadow.

With "Dark Emperor, and Other Poems of the Night," Sidman set out to answer this question: Why do creatures come out at night?

The poems made their own art, with their "pale scarves of clouds" and mushrooms that "shoulder up without a sound." But she also gave each forest character a perfectly factual paragraph about its traits or behaviors.

"With my children's work, it's addressing just the wonder of what goes on every day, the mysteries of what happens in nature, the feeling you want as a writer of being amazed by life, and feeling it the way that a child does -- new and fresh in the connections that you're making."

Words came first and, although she could comment on sketches that Rick Allen prepared over the course of the next year, she rarely did. "If I interfered in that, it would stifle him creatively."

While words and art combined become more than the sum of their parts, Sidman said editors such as Ann Rider perform the alchemy. "Ann is so wonderful because she can think intuitively in the same way that writers and illustrators work," she said.

In Sidman's mind, the book looks a lot like the natural marshy area in Orono where she walks her dog. And while she walks in the light, she allows as how she's no longer quite as afraid of the dark.

"Of course not," she said. "Are you?"

THE ILLUSTRATOR

Much of Rick Allen's Duluth childhood was spent in the old Carnegie library, which apparently never got rid of a book.

That resulted in overlooked volumes filled with "fine engravings and over-the-top graphic images," he said. "So it got in the bone and marrow early on."

Allen's prints for "Dark Emperor" are pictures within pictures, all fine engravings and bosky colors. Moonlight catches a raccoon's tail, while porcupettes peer as if unaware of their quills. Did Allen know there were such creatures as porcupettes, which is what baby porcupines are called?

"No," he said, laughing. "But once you do know, how could there not be?"

This, his first children's book, required a different mind-set from the note cards and posters that are at the heart of his shop, Kenspeckle Letterpress in Duluth.

Editor Ann Rider's proposal "to develop sequential, linked and cohesive images was intriguing," he said, compared with being what some art directors regard as merely "the hand."

"Part of Ann's genius -- we all see genius when someone agrees with us -- is she just sort of cuts you loose. I got feedback, but little direction. Of course, interference is direction by another name. But she creates an atmosphere where you want to do your best work because there's such a degree of trust involved."

He knew that Sidman had little recourse but to trust him, as well. "It must be a tremendous vexation of the spirit for an author to turn over her work so a left-handed bear can draw pictures."

The process, from sketches to finished prints, took almost two years. "It's a fine line between just making a commercial collaboration and something that might have some artistic interest," Allen said. Of his penchant for working hidden animals into some drawings, "you want to give people something to come back and look into. Kids love to look and discover."

Ideally, "Dark Emperor" is that rare picture book that works for kids and for adults. Allen quoted Scottish poet Robert Burns' "Epistle to a Young Friend," in which he says of an artistic effort, "Perhaps it may turn out a song/Perhaps, turn out a sermon."

"In this case," Allen said. "I'd actually like to think this book is a song."

KIM ODE