I don’t remember the exact day that I finally went up to the third floor. You’d think I would, but I’m no good with dates—I can’t remember my own birthday, let alone anybody else’s. I know it was early in May, and I know it was a Tuesday afternoon, because Sally was in Dorchester with her two piano students—no, she’d picked up a third one by then. Julian had stayed in Sherborne after school for some cricket match. Evan was over at a neighbor’s farm, helping out with some drainage problem, and I think Tony was with him. Either that, or he’d stayed for the cricket match, too, I’m not sure now.

I was sitting under the chestnut tree out behind the dairy, writing a letter to Marta, when Mister Cat’s ghostly girlfriend trotted by. She looked different in broad daylight—fainter, for one thing, and definitely transparent, but more real, too, maybe because it was daylight. She got a few steps past me, and then she suddenly turned and looked at me.

I have never watched Lassie on TV. Not when I was little, not when I was thirteen—I’d watch game shows, which I hate, rather than watch Lassie. I’m making a big point about that, so it’ll be clear that I didn’t imagine for one minute that she was trying to get me to follow her. I got up and followed her just because I wanted to. Because I wanted to know what the hell ghost-cats do on a warm Tuesday afternoon in Dorset. That’s all. I may wonder about it now, sometimes, but it was my idea then.

The Persian never looked back. She cut straight past the dairy, past Evan’s workshop, that used to be the cider house, and right under the nose of Wilf’s pet billygoat (he had the temperament of a werewolf and a thing about Mister Cat, but he never saw her) into the Manor. I thought she’d just fade through the door, like a special effect, but she used the cat-flap Evan had put in, the same as Mister Cat. It twanged back and forth a couple of times after she’d passed in, just as though a real cat had been there.

I was right behind her, practically stepping on her tail, but she didn’t pay me any more heed than if I’d been a ghost myself. Straight up the stairs to the second floor, straight toward the east wing, swishing that feather-duster tail behind her like one of those fans slaves wave over emperors in movies. The house was so still that I could actually hear her feet padding on the hard old floors—or maybe I wasn’t hearing real footsteps but the ghost of footsteps, the shadow of footsteps. Hard to be sure, when you don’t know the rules.

I was following her so closely that I can’t say exactly when Mister Cat materialized beside me. He was just there, for once not scampering after his deceased Persian patootie, but stalking along at my heel, all dignity now, sort of convoying me like a tugboat, escorting me—where?

At the foot of the east-wing stair, she turned again, and her eyes were glowing green as pine needles in sunlight. Mister Cat did go to her then, and they stood nose to nose, not saying anything I could hear—just looking over at me together from time to time. It got on my nerves, so I finally said, “Enough already. Let’s do it.” And I started for the stairway.

They went up ahead of me. Once I’d pushed the boards and rubbish aside, those two shot past me and vanished into the darkest darkness I’d ever seen—a darkness that didn’t have a thing to do with the sun rising and setting. An old darkness that knew itself. When I started up, I felt it tasting me, licking at my neck and my face—daintily, carefully—the way Mister Cat will lick at something he isn’t sure he wants to eat. But I kept climbing, out of pure plain stubbornness. I’m not proud of the cranky way I still get sometimes, but I can tell you it has its uses. There’s a line in the Bible about perfect love casting out fear. That I don’t know about, but orneriness will definitely do it every time.

It was lighter on the third floor, because of the high window at the far end. I could see clouds and sky, and the top branches of that same tree I’d been sitting under. The cats were halfway down the hall, and I walked toward them, already feeling a sneeze coming on, because the dust was so thick everywhere. But a sneeze was fine, a sneeze was ordinary—nothing ghostly or spooky about a sneeze. The third floor was turning out to be a floor, that was all— closed doors and cold dust, a couple of tottery old cabinets, a few faded portraits hanging above curved sconces, candleholders. Dimness, not darkness.

Mister Cat and the Persian were waiting for me, not at a door, but at a narrow panel on the left side of the corridor. It wasn’t any different from any other section of the wall: same grungy oak trimmed with the same ivy-leaf molding, top and bottom, with the same chipped, bruised satyr faces peeking through at the corners. There was a bigger face about a third of the way down, looking like a lion, or maybe a sunflower with teeth. The other panels had that one, too, but this lion had little hollows for eyes, as though they were supposed to hold bits of bright glass, or jewels.

Just as I got there, the Persian gave that distant meow of hers and melted through the panel, the way I’d imagined she would when we came in from outside. She didn’t actually walk into it, though—she sort of gathered herself into a shapeless gray-green mist for just a moment, and then she flowed right through, all at once. Five seconds—tops—and gone.

Mister Cat and I stared at each other. It’s still the one and only time I’ve ever seen him looking as bewildered, dumbfounded and flat-out flabbergasted as I felt. He said, “Prrrp?” and I said, “How the hell do I know?” No doorknob, no hinges that I could see— maybe to everyone else who reads this, that’s a dead giveaway to a secret room, but it wasn’t for me. I felt over the panel, pressing hard on every single ivy leaf, or anything else raised. I even tried pressing the lion-head’s empty eyes, because why not? Nothing. Mister Cat meowed impatiently. I said, “I’m trying.”

Then I thought, if there had once been stones of some kind in the lion’s eyes, maybe they’d rested on something under the sockets. I dug in my pockets until I came up with a paper clip, bent it straight, and started poking around the hollows. Right eye, nothing—left eye… left eye, a little hole at the bottom of the socket… a soft click, and a louder click after that… and suddenly daylight around the molding, and the panel swinging back, very slowly. I remember, I saw one corner of a painting, and the legs of a chair.

Mister Cat was through the crack so fast you’d have thought his kibble dish was on the other side. But I stood right where I was, because there was a third click—this one in my head—and I realized that what was beyond that panel had to be the room that we never could find in the house plan, or in any of the paintings of the house; the room whose pointy window never reflected the sun. And when I realized that, I wanted to run, but I didn’t. I stood there, not moving, for maybe a month, maybe two, and then I pushed that secret door the rest of the way open.

And there was Tamsin.