In short, it was both the best three days I’d ever had, my mother notwithstanding, and a fairly standard week with Charlotte Holmes. My sister, unused to this phenomenon, was completely overcome. Shelby had taken to trailing Holmes like a shadow, dressing in all black and straightening her hair, dragging her away to show off things in her room. I didn’t know exactly what things were, but from the lilting, earnest music coming from under the door, I had a feeling that their soundtrack was L.A.D., Shelby’s boy band du jour. My guess was that Shelby was showing off her paintings. My mother had told me that my sister had taken up art with a passion while I’d been away, but that so far, she’d been too shy to show anyone what she’d made.

Not that I would have known what to say to her about it. I didn’t know a whole lot about art. I knew what I liked, what made me feel something—portraits, usually. I liked things that felt secret. Scenes set in a dark room. Mysterious books and bottles, or a girl with her face turned away. When asked, I trotted out Rembrandt’s Anatomy Lesson as my favorite work of art, though to be honest, I’d lost the ability to call it up clearly in my head. I tended to spend too much time with my favorite things, loved them too hard until I wore them down. After a while, they became more like a shorthand for who I was and less like things I actually enjoyed.

“Shelby wanted my advice, and I know enough to give her my opinion,” Holmes was saying. I’d asked if she’d been talking to my sister about her art. It was our last night in London; we were leaving for Sussex the next afternoon. My mother had turned my bedroom into a study, so we were where we’d been all week—on a pair of hideaway mattresses in the living room, our bags stacked behind us like a barricade. The sky outside was beginning to lighten. One tradeoff of being friends with Holmes was sleep. As in, you never did again.

“Enough?” I asked.

“My father thought it was an important part of my education. I can go on endlessly about color and composition, thanks to him and”—she scowled—“my old tutor, Professor Demarchelier.”

I propped myself up on one arm. “Do you . . . make art?” It struck me, then, how little I knew about her, how all the facts of her life before this September had come to me either secondhand or in bits and reluctant pieces. She’d had a cat named Mouse. Her mother was a chemist. But I had no idea what her first bought book had been, or if she’d ever wanted to be a marine biologist, or even what she was like when she wasn’t wanted for murder. She played the violin, of course, and so I imagine she’d tried out other kinds of art as well. I tried to imagine what a Holmes painting would look like. A girl in a dark room, I thought, with her face turned away, but as I watched her, she tilted her face toward me.

“I don’t have the skill, and I don’t invest my time in things I’m rubbish at. But I am a fair critic. Your sister is quite good. A nice sense of composition, an interesting use of color. See? There you go. Art talk. Her range is limited, though. I saw about thirty paintings of your neighbor’s dog.”

“Woof is usually sleeping in their backyard.” I smiled at her. “Makes him an easy subject.”

“We could take her to the Tate Modern. Tomorrow morning, before we go. If you wanted.” She stretched her arms out above her head. In the darkness, her skin looked like cream in a pitcher. I jerked my eyes back up to her face. It was late, and when it was late, I had these kinds of slippages.

I had them all the time, if I was being honest. At four in the morning, I could admit to that.

“The Tate,” I said, pulling myself together. Her offer had sounded genuine. “Sure. If you actually want to. You’ve been really nice to Shelby already. I think you’ve heard enough L.A.D. for a lifetime.”

“I love L.A.D.,” she said, deadpan.

“You like ABBA,” I reminded her. “So I don’t actually know if that’s a joke. Next I’m going to find out that you wear a fanny pack in the summer. Or that you had a poster of Harry Styles in your room when you were eleven.”

Holmes hesitated.

“You did not.”

“It was Prince Harry, actually,” she said, folding her arms, “and he was a very good dresser. I have an appreciation for fine tailoring. Anyway, I was eleven years old, and lonely, and if you don’t stop smirking at me, I will come over there and—”

“Yes, I’m sure it was his fine tailoring you appreciated, and not his—”

She hit me with her pillow.

“To think,” I said through a mouthful of goose down. “You’re a Holmes. Your family’s famous. You could have maybe made it happen. Princess Charlotte, and the bad-boy spare. God knows you’re pretty enough to pull it off. I can see it now—you in a tiara, doing that screwing-in-a-lightbulb wave in the back of some convertible.”

“Watson.”

“You would have had to make speeches. To orphans, and general assemblies. You’d have to have your photo taken with puppies.”

“Watson.”

“What? You know I’m teasing. The way you grew up is just beyond me.” I was rambling, I knew it, but I was too tired to put the brakes on. “You’ve seen our flat. It’s a glorified closet. You’ve seen how my mother gets all weird and tight-lipped when you talk about your family. I think she worries that I’m going to go to the Sussex Downs and get sucked in by the decadent, mysterious Holmeses and never come back. And you smile politely and bite back whatever you actually think of her, and my sister, and where we live. Which, let’s face it, has probably taken a ton of effort on your part, because you’re not particularly nice. You don’t have to be. You’re fancy, Charlotte Holmes. Repeat after me. I’m fancy, and Jamie Watson’s a peasant.”