I stared at her. Mom jeans and an oversized sweater—borrowed from Abbie, I could deduce that much—and her face assiduously clean. The sun dappled her hair. I had no idea what she was thinking.

“Holmes,” I said slowly, “how is this not a warning from August Moriarty?”

“It’s not. It’s a woman’s work, Watson, clearly.”

“So . . .”

“Nurse Bryony,” Holmes said, as if it was obvious. “Do you really think Phillipa is likely to be visiting a Delta Delta Delta website? More so than the woman who spent all of homecoming requesting old R. Kelly songs and telling me about her sorority formal? The profile is an excellent fit.”

“But the perfume points right back to August.”

“She most likely wears it too.” Holmes shrugged. “Stranger things have happened.”

“Have you smelled it on her?”

“People don’t wear the same perfume every day, Watson. I’m sure I’ll find a bottle in Bryony’s flat. It’s in Sherringford Town, and we can search through it while she’s away.”

“Holmes. How does this explain anything about the dealer? Or the forger’s notebook? Or the guy in the morgue?”

“Do you not trust me to have this worked out?” she said. “Because I do. They employed one agent, and that agent failed. So they hired another. There. It’s sorted.”

“Holmes—”

“Earlier, when I spoke to Detective Shepard, I asked him to bring Bryony in for questioning tomorrow at ten a.m. We’ll toss her flat then.” She gave me a sympathetic look. “I know the feeling. I’m always disappointed at the end of a case. But we’ll find another.”

I was beginning to believe it, now, what she’d said about the dangers of caring too much. How emotions only got in the way. It sounded to me exactly as though Holmes was ignoring some obvious conclusions in favor of devising any theory that let August Moriarty off the hook. How hard would it be for him to plant a typo, or to use a special font, to write this note the way a woman would? He knew what Holmes would look for, how she’d interpret it: he could feed her exactly what she wanted to see.

The worst part? She’d kept on buying that perfume he’d given her. Even though it was expensive. Even though she hated it. It was foreign, and hard to find, and that letter was doused in it.

I knew what I had to do.

“It’s a good plan,” I told her. It would be one, too, if there was any chance Bryony Downs was guilty. “But look, I still feel really awful from yesterday—I didn’t sleep much, thanks to your sense of timing, ha—and the pancakes smell amazing, but you know, Malcolm got me up so early—I think I need to—”

“Are you all right?” she asked. I was beginning to sweat.

“I feel terrible.” The truth. “I need to go lie down.” Also the truth.

“Go,” she said, waving me away. “I’ll wait for the detective. And maybe I’ll go through the note with your father again. He can’t follow my reasoning.”

I ran into my father at the foot of the stairs. “Can I see that file?” I asked him in a whisper.

He looked at me sadly. “In my study, upstairs. In the second drawer.” He had a kind face, my father. I’d remembered a lot of things about him when we moved to England: his dorky enthusiasms and plaid ties, the stupid nicknames he had for Shelby, the way my mother used to shout at him as he slumped at the kitchen table, head buried in his hands. But I’d forgotten how kind he was. How much he’d always trusted me.

“I’ll give you some space,” he said, and after I found his study, I locked the door behind me.

nine

I PUT THE FILE ON THE DESK.

My father had clipped things from newspapers, printed articles off the internet. It went chronologically: the oldest information was at the front. I resisted the urge to flip to the back.

No. I’d ease myself into it. Into betraying my best friend.

It started with the usual sorts of things. Sherlockian societies and book clubs. Fan sites for my great-great-great-grandfather’s stories, but far more for the film and television adaptations. Flipping through the pages, I found printouts from some of the fan sites that tracked the movements of the Holmes clan. They were intensely secretive, Holmes’s family, and so gathering kernels of information had become something of a sport for the greater world.

I folded out a taped-together family tree, one in my father’s own handwriting. Watsons, always the record-keepers. At the top, he’d placed Sherlock. Then came Henry, the son he’d had so late in life, categorically refusing to name the mother. I traced through Henry’s sons down to Holmes’s father, Alistair, and his siblings: Leander, Araminta, and Julian. A small line connected Alistair to Emma, Holmes’s mother; below that was a fork each for Milo and Charlotte Holmes.

I browsed through the articles about Holmes’s first case, when she tracked down the Jameson diamonds. In a photograph with her parents at the Met’s press conference, she stood pale and solemn-faced between her parents. On one side stood her father, looking at the camera with hooded eyes. Her mother had blond hair and a dark-red smile, one possessive hand on her daughter’s shoulder.

Enough of what I already knew. I flipped through to the last page and worked backward. Information on Leander Holmes’s charity. The page before it was a clipping from a Yard fund-raiser. And the one before that, like a lump of pyrite nestled into all that gold, was from the Daily Mail.