As I closed down the phone, my overwhelming emotion was a kind of desperate sadness—for Dr. Grant, for his daughter, and for this house, where it had all happened.

Unable to sit in silence with my thoughts any longer, I got up, put the baby monitor in my pocket, and, grabbing a ball of caterers’ string from the drawer by the cooker, I left the house by the utility room door, tracing the path the girls had shown me the day before.

*

The sun of the morning had gone in, and I was cold by the time I reached the cobbled path that led to the poison garden. It was strange to think it was June—down in London I would have been sweating in short skirts and sleeveless tops, and cursing the shitty air-con at Little Nippers. Up here, almost halfway to the arctic circle, I was beginning to regret not taking my coat. The baby monitor was silent in my pocket as I reached the gate and slipped my hand through the metalwork to try to trip the catch, as Ellie had done.

It was more difficult than she had made it look. It was not just the fact that the hole in the wrought iron was too narrow for my hand to fit comfortably, it was also the angle. Even after I had forced my hand through, swearing as the rust ripped skin off my knuckles, I could not get my fingers to the catch.

I changed position, kneeling on the damp cobbles, feeling the chill strike up through the thin material of my sheer tights, and at last managed to get a fingertip to the tongue of the latch. I pressed, pressed harder . . . and then the gate opened with a clang and I almost fell forward onto the worn bricks.

It was hard to believe that I had ever mistaken it for a regular garden. Now that I knew its history, the warning signs were everywhere. Fat, black laurel berries, the thin needles of yew, straggling patches of self-seeded foxglove, clumps of nettles, which I had taken to be weeds when I first entered the garden but which I now saw bore a rusted metal tag dug deep into the earth labeled Urtica dioica. And others too that I did not recognize—a plant with flamboyant mauve flowers, another that brushed my leg with a sensation like tiny needles. A patch of something that looked like sage but must have been something very different. And, as I pushed open the door of a tumbledown shed, a profusion of mushrooms and toadstools, still sprouting gamely in the dark.

I could not suppress a shudder as I drew the door quietly shut, feeling the damp wood grate on the flags. So many poisons—some tempting, some decidedly not. Some familiar, and some I was certain I had never seen before. Some so beautiful I wanted to break off a branch and stick it in a jug in the kitchen—except that I did not dare. Even the familiar plants in these surroundings looked strange and ominous—no longer grown for their lovely flowers and colors, but for their deadliness.

I hugged my arms around my body as I walked, partly to protect myself, but the garden was so overgrown that it was impossible to avoid brushing up against the plants completely. The touch of the leaves felt like prickles on my skin, and I was unable to tell anymore which plants were toxic to touch, or whether it was pure paranoia on my part that sent my skin itching and tingling when I brushed past.

It was only when I turned to leave that I noticed something else—a set of pruning shears, sitting on the low brick wall holding back one of the beds. They were new and bright, not in the least rusted, and looking up, I saw that the bush above my head had been pruned—not much, but enough to clear the path. And further up, I saw that a piece of garden twine had been used to hold back a swag of creeper.

In fact, the more I looked, the more I was sure—this garden was not as neglected as it appeared. Someone had been tending to it—and not Maddie or Ellie. No child would have thought of neatly cutting back that hanging branch—they would have snapped it off, or just ducked under it, if they were even tall enough to notice.

So who then? Not Sandra. I was sure of that. Jean McKenzie? Jack Grant?

The name sounded in my head with a curious chime. Jack . . . Grant.

It wasn’t an uncommon surname, particularly around here, but . . . still. Dr. Kenwick Grant. Could it really be coincidence?

As I stood, wondering, the baby monitor in my pocket gave a little grumbling squawk, recalling me to reality, and I remembered what I had come here to do.

Picking up the shears, I hurried back to the gate, and pulled it firmly shut behind myself. The clang as it closed set a flock of birds rising into the sky from pine trees up the slope, and seemed to echo back at me from the hills opposite, but I was in too much of a hurry now to care.

Taking the string out of my pocket, I clipped off a generous length and then I stood on tiptoes and began to wind it round and round the top of the gate, above the height of my own head, where no child could possibly reach, twining it in and out of the ornate fitting and round the brick lintel above, until at last the string was used up, and the gate was totally secure. Then I tied it in a granny knot, wrapping the ends around my fingers and pulling the string tight until my fingertips went white.

The baby monitor in my pocket wailed again, more determinedly this time, but I was sure now that the gate was secure, and that nothing short of a ladder would enable Maddie and Ellie to break in this time. Dropping the shears into my pocket, I picked up my phone and pressed the Happy app icon.

“Coming, Petra. There, there, sweetheart, no need to cry, I’m coming.”

And I ran up the cobbled path to the house.

*

The next few hours were taken up with Petra, and then figuring out how to drive the Tesla to collect the girls from school. Jack had taken the Elincourts’ second car, a Land Rover, with him to meet Bill, and had given me a quick crash course in driving the Tesla before he left, but it was an undeniably different style and it took me a few miles to get used to it—no clutch, no gears, and a strange slowing every time you took your foot off the accelerator.