“I got married young,” I say. I omit the fact that it might not have been one of the smartest relationship moves. “Had kids young, too. You got kids?”

Petroski hesitates, and the shy smile fades. “One. A girl. She turned a year old in April.” More quietly, he says, “One year. Can I ask you a question?”

“Sure.”

“Look, I’m no scientist or anything. I got a high school degree and some community college hours; then I joined up. Figured the army would give me a steady paycheck and all that. Plus, you know, if you make it twenty years you get a pension. Insurance and all that.”

“They do make it sound good,” I say.

He leans forward. “But I know something about kids. I’m the oldest, see. Have five brothers. Youngest one born when I was fifteen. Danny’s his name. Good kid.”

I nod. Sergeant Salt-of-the-Earth keeps going. “Danny knew what ‘no’ meant by the time he was five months old. Before he was one, he could say ‘Mama’ and ‘Dada’ and ‘Boo.’ Boo was the name of our dog. He didn’t make much sense, but he was talking. And then”—Petroski slaps the desk with the palm of his hand—“bang! Two words, questions, stuff like ‘Where Boo?’ and ‘Want juice.’ It was like some kinda miracle, you know?”

I do know. I watched four babies go through all those stages. Prelinguistic babbling, one-word holophrases, two-word sentences—usually nothing more than a subject and a predicate. Then, in Petroski’s words, bang. It all started happening. At three, Steven would make demands: Take me to school in the morning; Please make chocolate in the afternoon.

I also know the flip side, and so does Petroski.

“I saw this documentary once, ma’am,” he says. “Couldn’t watch the whole thing—too gruesome. These people, see, they kept their little girl locked up in a room and didn’t talk to her for something like twelve years. Twelve years, ma’am. You imagine?”

I shake my head, even though I can imagine. It’s happened in rare cases.

Petroski goes on, an armchair linguist who doesn’t realize how right he is. “So you take a kid—any kid—and if you let them talk, they do it. If you don’t”—another palm slam on the table between us: bang—“that’s it. Like they have some kinda clock inside ’em.”

“They do.” No need to mention critical period hypotheses, also known as the use-it-or-lose-it theory, to Sergeant Petroski. He gets the vibe without all the fancy jargon.

“So my question is,” he says, looking straight into my eyes. His own are calm and blue, but there’s pain behind them. “My question is what’s gonna happen to my own little girl if she doesn’t ever get to talk? Is she gonna turn out like that Genie woman? End up in some kinda home?”