I’ll never forget the first rejection I received from a literary agent. “This is a great premise,” she told me, speaking of my then-unpublished debut novel, The Witches of Willow Cove, “and the story is fun and fast paced. But what’s holding me back here is the age range of the book. I found myself wishing the characters were younger—11 or 12—and I wish this novel were more firmly rooted in the middle-grade realm, sticking to middle-grade topics, rather than skewing older.”

Like all rejections, it stung. But it didn’t sting quite as much as you might expect, because if there was one thing I knew about my book, even as an unpublished author languishing in the slush pile, it was who I’d written it for: the tweens and younger teens who’ve started to outgrow traditional middle-grade books, but aren’t yet interested in the themes they encounter in older-skewing young adult novels. What this agent was telling me was that she didn’t get my book, not really, so we wouldn’t have been a good fit anyway.

Don’t get me wrong—she was far from alone. I heard a lot of variations on this theme. “For one thing,” said another agent, “I think this falls squarely between middle grade and young adult fiction, which is a very tricky place to be. Characters in young adult are usually 16 and up,  and in middle grade, they’re often 12.”

“Would you consider aging down your characters and resubmitting it?” asked another. Then there was the agent who suggested I take the opposite approach and revise it into a young adult novel “with more sexual tension between the leads.” Which, just… no. That was not what I was going for at all.

But the message, no matter the delivery, usually boiled down to something like this: Nobody knows where to shelve a book with a 13-year-old protagonist, let alone one like mine that’s the first in a trilogy and will see the characters age to 14 in book two and 15 in book three. Where do you put such a series in a binary world that defines middle grade as 8 to 12 and young adult as 16 to 18?

The answer, of course, is upper-middle grade. And thankfully, even since the time I began querying The Witches of Willow Cove, that’s a space that seems to be growing again after a fairly long lull. Kate Foster has created a phenomenal list of books with 13-year-old protagonists here, if you’re interested in seeing the breadth and scope of books in this category.

It wasn’t always such a struggle to find a home for upper-middle grade novels. Arguably the best Harry Potter books are The Prisoner of Azkaban, The Goblet of Fire, and The Order of the Phoenix—in which Harry, Ron, and Hermione age from 13 to 14 to 15 over the course of the three books. In the Percy Jackson novels, he’s 12 at the beginning of The Lightning Thief, 13 in Sea of Monsters, 14 in The Titan’s Curse and The Battle of the Labyrinth, and 15 at the start of The Last Olympian.

If you ask me, it’s no coincidence that these are among the most popular kids’ books of all time. I think a lot of kids actually crave upper-middle grade novels with longer, more complex storylines, characters in their early teens, and thematic elements that bridge the gap between younger children and older teenagers.

I think we need more books like this—lots more—and that’s one of the reasons why I set out to write The Witches of Willow Cove with dual main characters, one a magical 13-year-old girl who discovers she’s descended from a long line of witches, and the other an ordinary 13-year-old boy with no magical powers to speak of—but more than enough loyalty, smarts, and bravery to make up for it.

In my novel, I wanted my characters to deal with things like first crushes, navigating changing friendships, discovering hidden reserves of strength and empathy, learning that not all authority figures are trustworthy, and most of all starting down that path toward becoming who they’re meant to be as they grow into older, more mature people.

When I think about my own early teenage years, I’m struck by how much of who I am today was shaped by that time in my life. I can easily recall the feelings of my first crush, my love of all things Spider-Man and Star Wars, the friends I made, the books I read, the morals and values I developed then and still hold today—they’re all still there, clear as day to me, because the person I am now was forged in those years when I was first starting to figure out who I wanted to be.

To me, that’s the power of upper-middle grade. Sure, some bookstores may still not know where to shelve it, and maybe some publishers don’t yet know how to sell it, but I know for certain there’s an audience for it. And as writers, I know it’s up to us to give it to them.