"Why is the ocean blue?"
"Every night, when you go to sleep, the fish take out guitars. They sing sad songs and cry blue tears."

"What is the rain?"
"The tears of flying fish."

So begins Mac Barnett and Isabelle Arsenault's tender picture book collaboration, Just Because. A series of questions and beautifully outlandish answers, the soft call-and-response style of the book soothes and entertains as each rejoinder is more inventive than the last.

A young girl is tucked snugly into bed in an evening-dark room, a small dog wearing a cute little bow is sprawled on her comforter. Both girl and dog are awake and alert despite the late hour. The door to the bedroom is open and her father peeks in, the hallway light spilling around him. On the left-hand page, in a blue circle on a black background, we see the question: "Why is the ocean blue?" The page turn reveals a double-page spread in shades of gray, blue the only accenting color. Two fish--one sporting sunglasses, the other wearing a cap--strum guitars, their mouths wide open, tears spilling.

The little girl turns to her dad, who has moved a little further into the room, making the shadow-shapes on the wall shift and change. "What is the rain?" Dad's arms are crossed and shoulders hunched as he comes up with his next answer. The page turn reveals a grayscale illustration of flying fish moving in a school above a quaint city. One fish has a hat tied to his head with a tiny bow around his gills; another wears a beret; all are crying.

Next is a fiery red circle on the question page: "Why do the leaves change color?" Dad sags against the door jamb, a far-off look on his face. "In autumn, when the world gets colder, the trees keep warm by setting quiet little fires in their leaves. By winter, their branches have all burned up." On the page turn, the bright, bold red of the background is a stark contrast to the dark birds and branches in the foreground. Birds warm themselves around a tiny little fire made of one single, solitary leaf. Dark smoke rises above them and spills off the page as dozens of little spark-of-light leaves burn around the birds. (More hats here, too--three of the birds are wearing winter beanies, one with a handsome pompom on top.)

Now it's the girl's turn to have a far-off look. Dad, however, is entirely in the bedroom now, standing next to the bed, hands on hips, a pleased look on his face--he's found his rhythm. The dog looks at Dad while the girl looks into the distance: "Why do birds fly south for the winter?" It's obvious, isn't it? "To fetch new leaves for the trees." The double-page spread features a lush, vibrant green that matches the question-circle from the page before. A tangle of plants fills the left-hand page, spilling over the gutter onto the right. Two birds fly off, new leaves clutched in their beaks, hats fitted snugly atop their heads or tied under their chins in happy little bows. A tiny insect waves goodbye from the tangle.

The little girl is exploding with inquiries, and brightly colored question-circles fill an entire double-page spread: "What is a volcano"; "Why do we sneeze?"; "How does an egg become a chicken?" Of course, this game can't continue all night, and Dad finds a way to bring the questions to an end. As Dad leaves, readers get their first glimpse at the other side of the girl's room, where a guitar, a fish and several bird figures (among other things) can be seen.

Just Because is a meticulously planned, "carefully structured" picture book, with deliberate thought behind both text and illustration. "It's a catechism," Barnett says, "The questions and answers are arranged in couplets: the father's first answer unfurls a wild and sprawling premise; his second answer snaps things shut in iambic trimeter. (The final couplet reverses this rhythm.)" This arrangement, he hopes, "creates a pleasant cadence and provides narrative energy." The back-and-forth between child and father is both calming and wholly enjoyable, creating a book that could easily be read aloud to a single child or a large group.

Arsenault's gouache, pencil, watercolor and digital illustrations enhance Barnett's text, the color palette fitting within the same strict parameters as his words. Each double-page spread features the color from the page before, until there are no more questions to ask and all of the colors appear together. Like the text, every illustration is magnificently imaginative, the boundaries of the ideas moving far beyond the confines of the picture book's structure. Arsenault's illustrations also give the book continuity, tying all of the couplets together with recurring visuals that connect the real world with the imagined. Sweet and friendly, sassy and silly, Just Because is likely to strike a chord with parents and will almost certainly be adored by children. Why? Just because.

photo: Carson Ellis

Mac Barnett is the author of many books for children, including Caldecott Honor Books Extra Yarn and Sam and Dave Dig a Hole, as well as the Shape Trilogy, all illustrated by Jon Klassen; President Taft Is Stuck in the Bath, illustrated by Chris Van Dusen; and the New York Times bestseller Mac B., Kid Spy: Mac Undercover, illustrated by Mike Lowery. Barnett lives in California.

The premise of Just Because reminds me of a certain comic-strip father who would give absurd and outlandish answers to everyday questions from his stuffed-tiger-loving son. Where did you get your inspiration for Just Because?

I'd forgotten about those strips with Calvin's dad! Calvin and Hobbes was so important to my childhood, it may indeed have been a spice in the primordial soup from which Just Because sprang. But this story owes more to Arkady Leokum than Bill Watterson: I loved big books of scientific questions when I was a kid, but my mind tended to stray toward the fantastic. It still does.

When writing this book, what did you start with: question or answer?

I started with the questions, a long, long list of questions, which, like the dad in this book, I tried to answer, moving things around until I had a shape I liked.

Did you specifically set out to write something soft and quiet?

I think this book has an intimate tone, dream logic and reassuring rhythms, but it also has erupting volcanoes, a T-Rex in space and fish playing guitars. There are certainly books that are particularly good for a classroom full of kids, and books that are meant to put kids to sleep. I've written books that I definitely would not read to a kid at bedtime. But I think most of my picture books make for a good nighttime read. And even though the story in Just Because takes place at bedtime, I'd happily share it with a gymnasium full of first-graders.

It feels like we're seeing a new Mac Barnett book every year. How are you maintaining that pace? What is it like to have a seemingly inexhaustible repository of ideas?

Lots of my job as a writer is sitting around my house not writing. This stuff doesn't come easily to me, or quickly--most days I feel frustrated with myself for not getting anything done. I'm surprised when I look at the calendar and see I have books coming out. I don't really know how it happens.

Is there anything else you'd like to tell Shelf readers?

I've been saying for almost 10 years that if I could work with any illustrator in the world, it would be Isabelle Arsenault. I can't believe I actually get to.

photo: Dominique Lafond

Isabelle Arsenault is the author/illustrator of Alpha and the illustrator of several other books, including Captain Rosalie by Timothée de Fombelle; Jane, the Fox, and Me by Fanny Britt, a New York Times Best Illustrated Children's Book of the Year; and Cloth Lullaby: The Woven Life of Louise Bourgeois by Amy Novesky. Arsenault is a three-time recipient of the Governor General's Literary Award. She lives in Montreal.

Just Because has very little text, composed entirely of the little girl's questions and the father's creative answers. What was it like to turn that manuscript into a 40-page, illustrated picture book?

Mac's script already included layout indications: the rhythm was planned, with the girl's questions on a first spread and the father's answers on the next. Since the text was very simple and had just a few words, it allowed me to use the space available and deploy my vision, creating visuals that would complement the text and offer possible interpretations to the story. I love being able to give my narrative input to a story and with this book, it was quite possible.

Throughout, the questions are asked in black text, each on a colored circle. The answer landscape is then illustrated in a palette that features the question's circle color. How did you come to this illustrative decision? What is its significance?

A different color was used to create a unique mood and setting for each of the girl's questions. It also helped create a visual link with the answer pages. Then, when the reader comes to the last spread, all the colors come together in a single illustration where everything is possible, like in a dream. This was a visual way of supporting the manuscript and guiding the reader through a story that had very little text.

I like to use color as a narrative tool. The blue and gray spreads take place in the little girl's bedroom--in real life--where she is asking her father questions. Those pages are dimmer, because the lights are turned off in her bedroom, right before bedtime. The answer pages feature more colors, reflecting the little girl's imagination as she listens to her father's answers. On those spreads, we see her vision of the world, based on her own references--more naïve and colorful than real life.

What did you like best about working on this particular book?

I especially liked the concept of the book because it gave me a lot of visual freedom. Working with a team that supported my ideas and approach was also uplifting. From the beginning, I felt inspired by the absurd touch to the story. It felt very refreshing compared to many other picture books nowadays.

Is there anything else you would like to tell Shelf readers?

I hope you enjoy the book!