Diana switched the light on and descended from the third floor, clinging tightly to the bannister. I was still blinking in the glare when she caught me by the wrist, her grasp so brittle that I couldn’t resist, in case I hurt her.

“Wait,” she repeated, even though I was waiting—like it or not. Her touch was an icy wind blowing over my skin and bringing me out in goose bumps, and I wondered how long she’d been loitering on the stairs when it was obvious she ought to be in bed. With none of the armoury—the strong shoes, the walking stick, the death-mask make-up—that had kept her together yesterday afternoon, she looked ancient and profoundly unwell. Her dusky-pink pyjamas might have suited a film-noir beauty from the 1940s. The silk jacket was made to accommodate a pillowy bosom but it hung loose over Diana’s chest, and she’d had to make a bulky knot at the waist of the trousers just to keep them from falling down.

“You’re staring,” she said, letting go of my wrist to pull the collar together. It was a defensive gesture but regal, too, and I imagined her doing it in former times, when she was well—resting her fingers loosely on her throat and flashing costly jewellery at her party guests.

“You make me feel like a ghost,” she added, and if this was an attempt to make light of the situation, it didn’t show in her face. I tried to smile, but I couldn’t think of a single thing to say.

“We have to be quick.” She lowered her voice to a whisper and leaned forward, till I could smell the mint imperial on her breath and the staleness beneath it. “I need to talk to you about Stella.”

“Stella?”

Diana pressed a hushing finger to her mouth. She’d had pink lips yesterday, but today her mouth was just a thin, black line.

“Stella?” I whispered. “My sister, Stella?”

Everything urged me to run outside at once; everything except a niggling need to hear it—quickly, quickly—whatever it was. It wouldn’t be anything new. I’d read all the newspapers at the time, and the police report, and the coroner’s report, and Cory had told me about his tenuous connection—that had to be enough. There was no breathing space left for mystery.

“Let me tell you what’s going to happen,” she said, “if you don’t go away.”

“But I want to know what you mean about Stella—”

The front door opened down below and Cory’s voice flooded the stairwell.

“I’ll just grab a pair of shoes,” he called over his shoulder. “I won’t be a moment, and then I’ll give you the guided tour of the gardens.”