You can’t be sending me texts at midnight.

—this is an emergency.

I asked him where he was.

I went for a walk, he said.

Where?

Just around the neighbourhood. I couldn’t call from home.

I heard the scrape of his shoe kicking a stone along asphalt.

Listen, are you somewhere private? he asked.

Sort of, I replied, under my breath.

We could meet in the park. Near the school.

No, I can’t do that.

Just for five minutes.

I knew something must be wrong, but it was hard to gauge the severity of the problem from his voice.

I can’t come out, I said. Just tell me what’s going on.

He was silent for a long moment. I asked him if he was still there.

There’re others, he said quietly.

What do you mean?

Others who can hear it.

I took a moment to process what he was saying. How do you know? I asked.

There’s a guy I play basketball with, Julian Delgado?

I know Julian, I said. I had taught Julian two years ago.

We were playing earlier tonight and I told him.

My breath caught in my throat. What?

Just—

About us?

No, no, about the hum, he could tell something was up with me, and then he told me his mom suffers from it too. It gives her headaches. Keeps her up at night.

Lots of things do that, I said, not hiding my anger. Until now, we had been fastidiously discreet.

No, trust me, she really hears it, he insisted.

How do you know it’s the same thing?

Because I talked to her, he said, as my heart sank even deeper.

You talked to his mother?

I’m telling you she can hear it. She described it to me exactly. And then she told me she works for this couple on Sequoia Crescent, and apparently they can both hear it. And this couple? They know of others who can too, and they’re organizing a meeting.

I struggled to take in everything he was saying. What . . . what kind of meeting? I asked.

To talk about it. To figure out what it is.