I’ve lifted this entire plot from a daytime soap opera that I watched last month when I was off sick, I abruptly realize.

DI James gives me a penetrating look. “You would testify to this.”

Oh God. Testify is one of those very scary words, like tax inspector and lumbar puncture . I cross my fingers under the table and gulp, “Ye-es.”

“Did you see these people?”

“No.”

“What’s the name of the nursing home? What area is it in?”

I stare back at him steadily. I have no idea. I glance up at Sadie, who has her eyes closed as though recalling something from a long, long way away.

“Fairside,” she says slowly. “In Potters Bar.”

“Fairside, Potters Bar,” I repeat.

There’s a short silence. DI James has finished writing and is flicking his pen backward and forward.

“I’m just going to consult with a colleague.” He stands up. “I’ll be back in a minute.”

The moment he’s left the room, Sadie gives me a contemptuous look.

“Is that the best you could do? He’ll never believe you! You were supposed to be helping me.”

“By accusing random people of murder?”

“Don’t be such a goose,” she says dismissively. “You didn’t accuse anyone by name. In fact, your story was utterly hopeless. Poison? Whispered conversations in pubs?”

“You try making something up on the spot!” I reply defensively. “And that’s not the point! The point is-”

“The point is, we need to delay my funeral.” She’s suddenly about two inches away from me, her eyes intense and pleading. “It can’t happen. You can’t let it. Not yet.”

“But-” I blink in surprise as she disappears right before my eyes. God, this is annoying. I feel like I’m Alice in Wonderland. Any minute she’ll reappear with a flamingo under her arm, shouting, “Off with her head!”

Leaning gingerly back in my chair, half expecting that to disappear too, I blink a few times, trying to process everything. But it’s too surreal. I’m sitting in a police station, inventing a murder, being bossed around by a nonexistent phantom girl. I never even got any lunch, it occurs to me. Maybe this is all due to low blood sugar. Maybe I’m diabetic and this is the first sign. My mind feels like it’s tying itself up in knots. Nothing makes any sense. There’s no point trying to work out what’s going on. I’ll just have to go with the flow.

“They’re going to pursue it!” Sadie appears again, speaking so fast I can barely follow her. “They think you’re probably deluded, but they’re going to follow it up anyway, just in case.”

“Really?” I say incredulously.

“That policeman’s been talking to another policeman,” she explains breathlessly. “I followed them. He showed him your notes and said, ‘Got a right one here.’”

“A ‘right one’?” I can’t help echoing indignantly.

Sadie ignores me. “But then they started talking about some other nursing home where there was a murder. Sounds too ghastly. And one policeman said maybe they should put in a phone call just in case, and the other agreed. So we’re all right.”

All right?

“You may be all right! But I’m not!”

As the door swings open, Sadie adds quickly, “Ask the policeman what’s going to be done about the funeral. Ask him. Ask him!”

“That’s not my problem-” I begin, then hastily stop as DI James’s head appears around the door.

“Lara, I’m going to ask a detective constable to take a statement from you. Then we’ll decide how to progress.”

“Oh. Er… thanks.” I’m aware of Sadie glaring meaningfully at me. “And what will happen to…” I hesitate. “How does it work with the… body?”

“The body will be kept at the mortuary for now. If we decide to proceed with an investigation, it will remain there until we file a report to the coroner, who will demand an inquest, should the evidence be sufficiently credible and consistent.”

He nods briskly, then heads out. As the door closes I subside. I’m suddenly feeling shaky all over. I’ve invented a murder story to a real policeman. This is the worst thing I’ve ever done. Even worse than the time I ate half a packet of biscuits aged eight and, rather than confess to Mum, hid the whole biscuit tin in the garden behind the rosebush and had to watch her search the kitchen for it.

“You realize I’ve just committed perjury?” I say to Sadie. “You realize they might arrest me?”