The letter arrives on a Friday. Slit and resealed with a sticker, of course, as all their letters are: Inspected for your safety—PACT. It had caused confusion at the post office, the clerk unfolding the paper inside, studying it, passing it up to his supervisor, then the boss. But eventually it had been deemed harmless and sent on its way. No return address, only a New York City postmark, six days old. On the outside, his name—Bird—and because of this he knows it is from his mother.

He has not been Bird for a long time.

We named you Noah after your father’s father, his mother told him once. Bird was all your own doing.

The word that, when he said it, felt like him. Something that did not belong on earth, a small quick thing. An inquisitive chirp, a self that curled up at the edges.

The school hadn’t liked it. Bird is not a name, they’d said, his name is Noah. His kindergarten teacher, fuming: He won’t answer when I call him. He only answers to Bird.

Because his name is Bird, his mother said. He answers to Bird, so I suggest you call him that, birth certificate be damned. She’d taken a Sharpie to every handout that came home, crossing off Noah, writing Bird on the dotted line instead.

That was his mother: formidable and ferocious when her child was in need.

In the end the school conceded, though after that the teacher had written Bird in quotation marks, like a gangster’s nickname. Dear “Bird,” please remember to have your mother sign your permission slip. Dear Mr. and Mrs. Gardner, “Bird” is respectful and studious but needs to participate more fully in class. It wasn’t until he was nine, after his mother left, that he became Noah.

His father says it’s for the best, and won’t let anyone call him Bird anymore.

If anyone calls you that, he says, you correct them. You say: Sorry, no, that’s not my name.

It was one of the many changes that took place after his mother left. A new apartment, a new school, a new job for his father. An entirely new life. As if his father had wanted to transform them completely, so that if his mother ever came back, she wouldn’t even know how to find them…