“The idea of gender is nonsense,” Meredith Russo tells me. “I think that if an alien looked at Elijah Wood in his early 20s and Tom Hardy, the alien would justifiably think, ‘Oh these are in no way meaningfully the same kind of human being.’ ” It’s an undeniably good point: Frodo and Mad Max don’t really have much in common.

What, then, does it mean to be a man? Or a woman, for that matter? Those questions are at the heart of Russo’s second novel, Birthday, which tracks best friends Morgan and Eric as they grow up in Thebes, Tennessee. Morgan struggles with understanding her identity as a transgender person and with the loss of her mother; Eric attempts to carve out an identity independent from his father’s cruelty and abuse.

 Every year Eric and Morgan meet up on their shared birthday, and the novel checks in on the kids and their relationship each time. That structure allows Russo to follow their progression and growth over the five years from their 13th birthday to their 18th. “Our storytelling tradition has trained us to expect that—maybe over the course of a week or a month or even a couple of months—we’ll have these revelatory experiences, these epiphanies, these adventures, whereas most of the important parts of adolescence are kind of a slow burn,” she says.

At each birthday, the novel switches between Morgan’s perspective as a trans girl grappling with her identity and Eric’s as a straight cis boy falling in love with her. “I wanted to give the partner his own side of the story and show his internality and show that he’s not stupid, he knows that she’s trans, he’s not being tricked, he’s just falling in love with this part of her,” Russo explains. Eric’s journey is about finding a way to reconcile those feelings (and his own innate kindness) with the toxic version of masculinity his dad and elder brothers embody.

Morgan struggles with many of the same harmful ideas about the kind of person she is supposed to be but with the added circumstance of being transgender. Russo renders her anguish vividly, even when her choices are painfully self-defeating. “Morgan is an angry, messy, jittery, internally contradictory, confused person, which is to say a traumatized teenager,” Russo says. “I hope she further opens people up to the idea that we aren’t Barbie dolls. We are messy, dirty, occasionally unflattering, occasionally unreasonable human beings.”

Russo herself certainly doesn’t fit the perfectly feminine image prevalent to trans women in pop culture like Laverne Cox of Orange Is the New Black. She dates women, loves denim vests, and works at a tree service. She’s visibly queer in the South. “I bet it’s so easy to be queer and punk in Portland, and I’m here in Tennessee playing queer punkdom on hard mode,” she says. Nonetheless, Russo insists that it’s her home—she loves the food and the people and the natural beauty.

She understands why many queer people choose to leave but mourns the resulting loss of community. The conundrum is a self-reinforcing one. “Nobody sticks around and keeps themselves in danger to show the cisgender heterosexual people here that we’re just human beings like anybody else,” Russo says.

That lack of knowledge is one place fiction can make a profound difference. Russo recognizes that most of her readers will be cisgender, and she hopes that her books can help answer the questions they may have about what being trans is like. She rejects the idea that clarifying things like how a man can be straight if he dates a trans woman makes her books political talking points rather than textured stories, however.

“So much of the narrative of being LGBT or being a person of color or being disabled, so much of the nature of our day-to-day lives is influenced by pain and oppression and debasement or the expectation and fear of those things,” Russo says, “that leaving them by the wayside leaves those characters unrecognizable to me.”

 Alex Heimbach is a writer and editor in California.