The landline rang at twenty past two on a Tuesday, and because I was the only one home, I answered it.

We were the last people we knew who still had a house phone. Alistair insisted on keeping it. He said mobiles failed in storms, that you wanted a line that didn't depend on a battery or a tower. The truth, I came to understand, was simpler. The landline was his. It was listed under his name. It rang in a house he treated like a fortress, and he never once imagined it could turn against him.

For eleven years I had lived inside his rules. He framed them as devotion. He didn't like me texting male coworkers after hours, so I stopped. He didn't like me going to the reunion, so I sent regrets. He read my fitness app's location history the way other men read the sports pages, and when I asked him, just once, whether he ever felt I'd earned a little trust, he looked wounded and said that a marriage without total honesty was just two strangers sharing a mortgage. I believed him. I believed him so thoroughly that I policed myself harder than he ever could have. I declined drinks with the girls. I kept my phone face-up on the counter like an offering. I made myself small and called it love.

So when the phone rang that afternoon, I almost didn't pick up. We let it go to the machine for telemarketers. But I was passing the hall table with a basket of laundry, and habit moved my hand before my brain could object.

"Good afternoon," a woman said, brisk and tired in the way of someone reading from a script for the hundredth time that day. "I'm calling from the sexual health clinic. I have results for a patient at this number. Am I speaking with Alistair?"

I said no. I said I was his wife. There was the smallest pause, the kind a person makes when a door they thought was empty turns out to have someone standing behind it.

"I see," she said. "I'm sorry, I'm not able to discuss—" and then, audibly distracted, half to herself, the way an overworked person lets a sentence slip its leash: "—we really need a private line on these. His result came back positive, he'll need to come in for treatment and to notify partners." A beat. Then the procedure caught up with her. "Please have him call the clinic directly. Thank you."

The line went dead.

I stood in the hallway with the laundry basket against my hip and the receiver still warm in my hand. The robot vacuum bumped softly against the baseboard and reversed. The smart speaker on the counter, the one he'd configured to log every command, sat there blinking its little ring of light. The house he had wired for my supervision hummed around me, and the only thing it had ever caught was him.

I want to tell you I cried, but the first thing I felt was almost relief, an awful, clarifying relief, like the moment a fever finally breaks. For eleven years I had felt like a suspect in my own home, never able to name the crime. Now the crime had a name, and it wasn't mine.

He had given them the house number. That was the detail I kept turning over. A man so careful, so paranoid about traces and trails, had handed a clinic the one phone he didn't control because some part of him couldn't imagine consequences finding him here. The rules were for me. Exposure was for me. He'd built a glass house and lived in it certain the stones only flew one direction.

I didn't confront him that night. I made dinner. I asked about his day. I watched him eat across the table and tell me, unprompted, that he'd had a quiet afternoon at the office, and I understood that the surveillance had never been about protecting us. It had been a magician's flourish, all that misdirection, keeping my eyes on my own hands so I'd never look at his.

The next morning, while he showered, I called the clinic myself, as a patient. I made my own appointment. Then I called a lawyer. I did both before he'd finished his coffee, and he never heard a thing, because for once I used my mobile, the one device in our marriage he'd taught me to keep close and quiet.

He found out it was over the way I found out everything else, secondhand, after the fact, from a piece of paper. The petition arrived by courier. I'd given them the house address on purpose.

We don't have a landline anymore. I cancelled it the week I moved out. I kept the mobile. It rings sometimes, and I answer it whenever I like, and I have never once felt watched again.