Behind him is a very pretty girl of about seventeen. Her black hair is tied in a ponytail. She wears a white T-shirt with the logo of the Pittsburgh Pirates, and her smile is beautiful and broad. She is holding Willie’s hand. With her free hand she pulls a wheelie suitcase.

Willie breaks away from the girl when he sees me. We hug and kiss and exchange the usual: “How was the trip?” “Good. I had a tuna sandwich.” “How was the time with Grandma?” “Great. Uncle Cab and I played more Call of Duty. I always won.”

And then Willie says, “This is my friend Diane. I was in the bathroom, and she helped me.”

“Were you sick?” I ask.

“No, I was stuck,” says Willie.

Diane, whose voice is as sweet as her face, explains, “I was leaving the train just now, and I heard this little voice coming from somewhere I couldn’t quite place.”

“It was me,” offers Willie.

“It was coming from the bathroom. I guess Willie might have done something with the lock,” she says.

“You always tell me to lock the door, Mom, in a public place,” Willie says.

Diane says, “Your mom is absolutely right. Anyway, we found a conductor, and he had this little doodad that unlocked it, and here we are. A little late but present and accounted for.”

“Diane is the only person I talked to on the train except for the man who sold me the sandwich and a Kiwi Strawberry Snapple.”

“Willie’s a good boy, Ms. Ryuan,” Diane says. “You’ve got him well trained.”

I ask Diane if she lives in New York.

“Bed-Stuy, in Brooklyn,” she says. “Right near you.”

“I told her we live in Crown Heights,” says Willie.

“I’ll treat us all to a cab,” I say.

Diane goes through the proper “Oh, no, I couldn’t.”

Willie goes through the predictable “Oh, come on, of course you can.”

And I say the obvious “I insist.” Then I order an Uber.

I look at the screen on my phone, and the price is so high that I can’t help but say, “My God. They want ninety dollars!”

“Surge pricing,” the ever-smart Willie says.

“Why don’t we just take the number 3 train to the Kingston stop?” says Diane. “We can get it just downstairs.”

“Awesome,” says Willie.

I tell our new friend Diane that Willie is the only kid in New York who prefers the subway to a taxi.

“I sort of agree,” she says. “The subway’s the fastest…if it’s on time.”

“And that’s a big if,” I say. Then I add, “I suppose we have to go back upstairs to the big station area for the subway entrance.”

Immediately Willie says, “No. Look. There’s the number 2 train.” He points to a sign that indicates where the 2 and 3 trains stop.