They had a pediatrician of course. And a dentist. Jupiter had a vet, especially as her muzzle grayed and her hearing went and it took a full minute to get up from her bed for a walk. The twins had an orthodontist. Ben had an optometrist and an allergist. Roo had an orthopedist from the time he broke his wrist skiing the first winter after they moved, overconfident that his Wisconsin snow experience trumped his classmates’ rain, forgetting their Washington mountain experience trumped his Midwestern flat. Poppy, in the years to come, would have a whole host of ists and ologists. But Rosie and Penn stuck with Mr. Tongo.

They met with him online, rather than over the phone, so he could see their faces and they his and anything else he wanted to show them: to no one’s surprise, Mr. Tongo was a fan of the visual aid. He still favored his giant exercise balls over actual office chairs, and it gave Rosie and Penn the impression he was talking to them from a train, bouncing lightly up and down, rolling occasionally side to side. Then suddenly he would break off and rush about the room, in and out of the shot, on and off the screen, pulling books off shelves or models out of drawers or standing on the desk to make a point, even though that meant they could only see his shoes and the bottoms of his trousers.

This day, Rosie and Penn at first thought they’d clicked the wrong contact, for when they connected, the window opened onto what seemed to be a preschool classroom, pastel wooden alphabet blocks stacked into high-rises and skyscrapers, a city of wobbly block towers.

“Mr. Tongo?” Penn ventured.

No answer.

“Mr. Tongo,” Rosie called. All these years later, they still did not call him by his first name.

Still no answer.

“Is the Wi-Fi wonky?” Penn wondered. “Or maybe it’s a glitch on his end?”

“Disconnect and try again,” said Rosie.

Suddenly, they heard a roar. Godzilla lumbered into view. He lurched into one precarious building and another, turning all to ruin, before mounting one of the rubbled piles and facing the camera triumphantly. Around his neck hung a sign in Mr. Tongo’s neat block handwriting. It read: PUBERTY.

Godzilla was menacing enough until Mr. Tongo’s face loomed three times larger at his side looking ready to accept his Oscar nomination.

“Hi, Mr. Tongo,” Penn and Rosie chorused from somewhere between bemused and wary.

“It was me all along!” Mr. Tongo wiggled his plastic Godzilla as if they might need proof. “A monstrous welcome to us all.”

They smiled at him weakly. “How are you, Mr. Tongo?”

“Me? I’m wonderful. Delighted to be with you. Thrilled to see you both. So! Back to school. Such an exciting time. Quelles felicitations! Mazel tov!”

Penn found it remarkable that a dozen or so years of school was sufficient to keep everyone on an academic calendar for life so that even people like Mr. Tongo, who had no children, wished him a happy new year every September. It was as if those school years bred a nostalgia so deep into the cells that the body woke to it each fall as naturally as the squirrels in the park began their frenzied harvest, never mind the weather was still fine, the sun still gracing them all. “It’s very exciting,” he acknowledged, then added awkwardly, “thank you.”

“Most welcome, most welcome. So my friends, in honor of the new year, today I think it’s time we do a little after-school special: ‘Puberty Versus Blockers. A Love Story.’”

Rosie watched her eyebrows rise in the miniature window in the corner of her screen. “Oh, Mr. Tongo. Poppy’s only nine.” Had he lost count? “We’re years away yet. Years away.”

“Time flies like a banana, my dear.” His eyes actually twinkled. “When was the last time you two talked seriously about hormone blockers?”

Rosie recalled the Dueling Dinner with Marginny and Frank. They’d had squash soup to start, which meant it had been fall which meant it had been a year already. “It’s been a while,” Rosie admitted.

“Well, let’s do it!” Mr. Tongo clapped his hands together. “This is going to be fun!” Over the years, Penn’s brain had come to play, under Mr. Tongo’s promise of fun, the theme music from Jaws.

Rosie shook her head. “Puberty is later for natal males than natal females. It’s not time yet. It’s too early to be thinking about hormone blockers.”

“It’s too early to be taking them,” Mr. Tongo corrected gently. He was methodically bricking Puberty Godzilla into a prison of hormone blocks. “It’s exactly the right time to be thinking about them. You all have some tough decisions just ahead. Blockers, and for how long? Cross-sex hormones, and when? Surgeries, and which ones? All/some/none of the above? Hard stuff. Is Poppy worried about all this, do you think?”

“Not at all,” Rosie assured him.

But Mr. Tongo was not assured. “That’s what worries me. You know, it used to be there were no transgender kids. Your son would come to you in a dress, and you’d say, ‘No son of mine!’ or ‘Boys don’t wear dresses!’ and that would be the end of it. That kid would grow up, and if he made it through childhood and if he made it through puberty and if he made it through young adulthood, maybe, if he were lucky, he’d eventually find his way to a community of people who understood what no one ever had, and he would slowly change his clothes and hair, and he would slowly change his name and pronouns, and he would slowly test the waters of being female, and over years and decades, he might become a she. Or he might kill himself long before he got there. The rate of suicide for these kids is over forty percent, you know.”