“Where’s Ellie?” I yelled, directly into her face, and she pulled away and fled down the stairs, with me following.

In the entrance hall the noise was just as bad, and there, in the middle of the Persian rug at the foot of the stairs, was Ellie. She was crouched into a little ball, her arms wrapped around her head. All about her leapt the terrified dogs, released from their beds in the utility room, adding their frantic barks to the cacophony.

“Ellie!” I shouted. “What happened? Did you press something?”

She looked up at me, blank and uncomprehending, and I shook my head and then ran over to the tablet sitting on the metal breakfast bar. I opened up the home-management app, but when I tapped in my access code, nothing happened. Had I misremembered it? I tapped it in again, the dogs’ furious woofs like a jackhammer of sound against my skull. Still nothing. You are locked— I had time to read, before the screen lit up momentarily and then died—a red battery warning flashing for an instant before it went black. Fuck.

I slammed my hand onto the wall panel and the lights above the cooker turned on and a screen on the fridge began blasting out YouTube, but the music volume didn’t reduce. I could feel my heart thumping wildly in my chest, growing more and more panicked as I realized I had no way of turning this thing off. What a stupid fucking idea—a smart house? This was the least smart thing I could imagine.

The children were shivering now, Petra still letting out earsplitting shrieks of distress next to my ear as the dogs ran in circles around us, and I tried the power button on the tablet, more helplessly, not expecting the thing to work, and it didn’t. The screen was completely dark. My phone was upstairs—but could I leave the terrified children long enough to fetch it?

I was staring round, wondering what on earth I was going to do, when I felt a touch on my shoulder. I jumped so wildly I almost dropped Petra, and swung round accusingly to find Jack Grant, standing so close behind me that my shoulder touched his bare chest as I turned. We both took an involuntary step back, me nearly tripping over a stool.

He was naked from the waist up and had plainly been asleep, judging by his rumpled hair, and he bellowed something, pointing at the door, but I shook my head, and he came close, cupping his hands around my ear.

“What’s happening? I could hear the din from the stables.”

“I have no idea!” I yelled back. “I was asleep—maybe one of the girls touched something—I can’t get it to turn off.”

“Can I try?” he shouted, and I felt like laughing in his face. Could he? I would kiss him if he succeeded. I shoved the tablet at him, almost aggressively.

“Be my guest!”

He tried to turn the tablet on and then realized, as I had, that it was out of power. Then he went to the utility room and opened up a cupboard there, the one where the Wi-Fi router was kept, along with the electricity meter. I’m not completely sure what he did in there, I was too busy comforting an increasingly distraught Petra, but all of a sudden everything went pitch-black, and the sound stopped with an abruptness that was disorienting. I found my ears were ringing with the aftermath.

In the silence, I could hear Ellie’s panicked gasping sobs and Maddie rocking back and forth.

Petra, in my arms, stopped crying, and I felt her little body go stiff with surprise. Then she let out a gurgling laugh.

“Night night!” she said.

Then there was a click, and the lights came back on—less brightly this time, and fewer of them.

“There,” Jack said. He came back through, wiping his forehead, the dogs padding in his wake, suddenly calm again. “It’s gone back to default settings now. Bloody hell. Okay.”

There was sweat on his forehead in spite of the chill in the air, and when he sat down at the kitchen counter, the tablet in his hands, I could see his hands were shaking.

Mine, as I set Petra beside Maddie, were trembling too.

Jack plugged the tablet in and now he put it down to wait until it had enough charge to turn on.

“Th-thank you,” I said shakily. Ellie was still sobbing in the hallway. “Ellie, there’s no need to cry, sweetie. It’s okay now. Look . . . um . . .” I crossed the kitchen and began rummaging in the cupboards. “Look . . . here we are, have a jammie dodger. You too, Maddie.”

“We’ve brushed our teeth,” Maddie said blankly, and I suppressed a hysterical laugh. Fuck teeth, was what I wanted to say, but I managed to bite it back.

“I think just this once, it’ll be okay. We’ve all had a shock. Sugar is good for shock.”

“Aye, it’s true,” Jack said, rather solemnly. “Back in the old day they’d make you drink sweet tea, but since I don’t really like sugar in my tea, I’ll have a jammie dodger too, thanks, Rowan.”

“See?” I handed one to Jack and bit into one myself. “It’s fine.” I spoke around the crumbs. “Here you go, Maddie.”

She took it, warily, and then shoved it in her own mouth as if I were about to take it away again.

Ellie ate hers more slowly.

“Mine!” Petra shouted, holding up her arms. I gave a mental shrug. I wasn’t going to win any prizes for child nutrition, but I no longer gave a fuck about that. Breaking one in half, I gave her a piece of biscuit too, and then threw a chunk to each of the dogs for good measure.

“Okay, we’re up and running again,” Jack said, as Petra began joyfully stuffing the biscuit into her mouth. For a minute I didn’t realize what he meant, and then I saw that he was holding the tablet, the screen casting a glow onto his face. “I’ve got the app open. Try your PIN first.”

I took the tablet from him, selected my username from the little drop-down menu, and put in the PIN Sandra had given me for the home-management app.

You are locked out, flashed up on the screen, and then when I tapped the little i button next to the message, Sorry, you have entered your Happy number incorrectly too many times and are now locked out. Please enter an admin password to override this, or wait 4 hours.

“Ah,” Jack said ruefully. “Easy mistake to make in the circumstances.”

“But wait,” I said, annoyed. “Hang on, that makes no sense. I only entered my pass code once. How can it lock me out for that?”

“It doesn’t,” Jack said. “You get three goes, and it warns you. But I suppose with all the noise—”

“I only entered it once,” I repeated, and then, when he didn’t reply, I said, more forcefully, “Once!”

“Okay, okay,” Jack said mildly, but he looked at me sideways beneath his fringe, something a little appraising in his eyes. “Let me try.” I handed him the tablet, feeling irrationally annoyed. It was clear that he didn’t believe me. So what had happened then? Had someone been trying to log in under my username?

As I watched, Jack switched users and entered his own PIN. The screen lit up briefly, and then he was inside the app.

His screen was laid out differently to mine, I saw. He had some permissions that I didn’t—access to the cameras in the garage, and outside—but not to those in the children’s bedroom and playroom, as I did. The icons for those rooms were grayed out and unavailable. But when he clicked on the kitchen, he was able to dim the lights by tapping on the controls on the app.