In Ryan T. Higgins’s latest picture book, Norman Didn’t Do It!: (Yes, He Did), a winsome porcupine discovers that he’s capable of comically horrible behavior when he becomes jealous of his best friend’s new friend. The twist is that both the best friend and new best friend are trees (the interloper is a seedling that appears one day), which leads to an unusual moral dilemma: “What if digging up your friend’s friend in the middle of the night and taking that friend very, very far away was NOT the right thing to do?” Speaking with PW from his backyard studio “in the southernmost town of Maine—it’s the Miami of Maine,” Higgins reflected on his character’s revenge and remorse, and what makes Norman different from other characters he’s created.

What makes the book both funny and poignant is that Norman projects so much onto the tree that’s his best friend. He’s named the tree Mildred, and imagines they have an incredibly rich relationship, even though Mildred is essentially unresponsive. Where did that idea come from?

Norman’s friendship with Mildred is really a friendship with himself, and all his conversations with the tree are one-sided conversations. That’s what got me interested in this character: it’s not just a story about two friends and another one coming in—everything is happening in Norman’s head. I’ve got three kids who are nine, seven, and two, and they’ve all had imaginary friends. How weird would it be if their imaginary friend got a new friend?

I also have memories of having a best friend and then a new kid moved to town, and that person became best friends with my best friend. It’s sort of a world-changing event: if my best friend has other friends, who am I? I remember thinking, “Who am I going to draw Ninja Turtles with?”

I wasn’t thinking about all this when I was making the book—I don’t actively think about deep things or big themes while I’m writing. But when I’m done, I’ll look back and realize that my subconscious had something to do with it.

Do you feel like Norman is a departure from your previous creations?

He’s definitely different. Bruce is grumpy and Penelope has an urge to eat children, but they get a hold of themselves and do the right thing. Norman gives into the urges that everybody has.

I was trying to channel a very silly version of Edgar Allan Poe’s “The Tell-Tale Heart.” I didn’t want Norman to cut down the new tree because that would be going too far [laughs]. But I do have him digging up the new tree and transplanting it, and because there’s a wheelbarrow and shovel and a hole in the ground, it nods to more nefarious things—and speaks to the shock Norman feels when he discovers what he’s capable of. I’ve never been able to put a grave robbery scene and murder in a picture book. It’s fun.

The story started off very mundane and linear: Norman was originally a beaver, and wouldn’t it be cool for a beaver’s best friend to be a stick? It had nothing to do with sharing or not sharing friends. My editor, Tracey Keevan [now at Sterling Children’s Books] asked what would happen if there were other trees nearby, and then the story started to write itself from there. The book is dedicated to Tracey and it’s my favorite dedication so far: “For my accomplice, Tracey Keevan, who shall remain nameless.” Because there is sort of a crime that gets committed in the book.

The artwork also feels like a departure from your other books. How would you describe it?

I did want to try something different. In the Bruce and Penelope books I have layered textures. Norman looks more graphic and less watercolor-y. The colors are flat and I don’t use a lot of gradients. It’s closer to a Sunday comic strip. I grew up on comics and they’re very big influences: Calvin and Hobbes, Peanuts, Mutts.

I also felt that because the story could get a little dark, I wanted to make sure the artwork was more light and fun—it made the dark parts more ridiculous.

What’s next for you?

I’m always making Bruce books: Thanks for Nothing, one of my Little Bruce books that’s seasonally themed, is coming out the same day as Norman Didn’t Do It! I do a Penelope book every other year—we’re wrapping up the final draft of a manuscript for the next one. And I’ve come up with an idea for the next Norman book that I’m super excited about. My greatest wish was to have a job that let me draw cartoons and pay the bills, and that’s what I’m doing now.

Norman Didn’t Do It! (Yes, He Did) by Ryan T. Higgins. Disney Hyperion, $17.99 Sept. 7 ISBN 978-1-368-02623-9