Life is a series of moments. And some of the most memorable ones—good or bad—come during high school. In her new YA novel, Infinite in Between (HarperTeen, Sept.), Printz Honor author Carolyn Mackler captures the high school moments of five teenagers who first meet when they are randomly assigned to the same freshman orientation group. The crew (two boys, three girls) write letters to their future selves and then agree to hide the notes in the school and to meet again at graduation to read them. Each chapter chronicles "the small moments, the ups and downs" of a single month during those four years, explains the author.

"I love stories that span periods of time," says Mackler. "You see how the characters evolve. They get a happily-ever-after moment, and then you turn the page and something terrible happens. High school is the perfect framework for a teen saga novel." It's perfect, she notes, because that adolescent span is particularly formative: "From the moment you start freshman year to the moment you end senior year, there are so many moments that happen that define who you are. You start as a kid and end up almost an adult."

And like most of us, Mackler has some kicker high school moments that are seared into her memory. "I was trying out for the school play and I still remember the sting of humiliation when my voice cracked and the cute boy I had a crush on, sitting in the front row, laughed," she recalls.

Mackler first appeared at BEA in 2001, so she knows the show well. It isn't a long trek to Javits from her Manhattan apartment, and she is pleased to be here. "It's the book," she says. "I'm so excited about it. I've been working on it for such a long time—three years. I kept coming back to it, to get it just right, and now I'm ready to share it with the world."

There's another reason Mackler is happy to hit the convention aisles this year: "I have a 10-and-a-half-year-old son who is an über reader," she says. "If I can score some hot galleys for him, I will win the ‘mom-of-the-spring award!'"

Next on her plate is a middle-grade novel for Scholastic. "I hope to have a first draft done by summer," she says. Her first foray into middle-grade fiction, Best Friend Next Door (Scholastic), hits shelves May 29. "I wanted to try something different and fresh," notes Mackler. "I wrote the novel I wish I had had in fifth grade—that was a difficult time for me."

Mackler signs galleys of Infinite in Between today, noon–12:30 p.m., at Table 13.

This article appeared in the May 28, 2015 edition of PW BEA Show Daily.