Joan grabs at the shears but Moriarty dodges, and continues to chop and slash at her hair. Tufts of pale gold drift to the kitchen floor. "Stop that!"

"No."

"Do I have to wrestle you for them?"

"Yes please." Now Moriarty is crying, the shears dangling from her small fingers, sobs shaking her body. She cries like a six year old, upright but limp, racked with misery.

Joan retrieves the shears and throws them in the sink. Moriarty's hair is now two or three inches long all over, except for one savage patch of nothing. "Enough," Joan says. "I'm making tea."

Moriarty slumps against the counter, then sees Sherlock's bedroom. When Joan turns with the teacups, Moriarty is arranged neatly on the sofa in there, like an intern awaiting their assessment, her face and body composed except for the pain in her eyes.

Joan sits beside her. They sip tea. It is surreal, but no more so than the rest of the past month.

"Two widows," says Moriarty.

"Hardly," says Joan.

"I need a drink," says Moriarty.

"This is a sober house," says Joan.

"Is it?"

Joan stares at her. Moriarty is enchanting, even with the car crash hair. Her terrible history is invisible behind her sly beauty.

"I need my bag," Moriarty says, in a tone of assumptive command so like Sherlock's that Joan just goes.

They sit, their backs to the smooth bed, and swallow brandy from Moriarty's hip flask. Moriarty sinks a little sideways with every sip, and Joan's head begins a slow painful throb. Her throat is burning.

"I miss him," Moriarty says. Her weight is on Joan's shoulder. She lifts her face and gives Joan the full blue eyes lip tremble single tear treatment. "You're my last connection to him, Joan."

Joan knows exactly what this is about but cannot shake off the weighty sense of Destiny lent by the brandy. It is like seeing your test grades on ridged vellum, the clumsy black type encapsulating your past efforts and probable future in a few terse lines: Found Sherlock, Found his nemesis, Lost Sherlock, Only nemesis remains. When Moriarty puts her hand on Joan's knee it feels inevitable.

Hugging your psychotic enemy in a weepfest of unhealthily repressed grief is one of the stupidest ideas Joan has ever heard. But Moriarty is clever and beautiful and completely right about the link to Sherlock, and this is not about sex, it is about love, and sadness.

It cannot last and so soon they are sitting, Moriarty more or less on Joan's lap, the flask in easy reach, and Joan is smoothing Moriarty hair in an automatic gesture of comfort and Moriarty is saying, "His kisses were always so awkward. Weren't they?"

"I never kissed him," Joan says.

"I know. I just wanted to hear you admit it." She swigs. "Still so jealous, even now."

"You knew that part of Sherlock," Joan says. "I knew his professional side. Only."

"Yeah, you tell yourself that, girl."

Joan sighs. She dislikes how accurate Moriarty is. "You need to go. I'll call you a cab."

"I want to stay," says Moriarty. She wriggles off Joan's lap and prowls the room. "I want to sleep in his bed."

"No!"

Moriarty spins to face Joan. "We can share," she suggests.

"No! I just, I, you know very well that there is too much alcohol and high emotion in this situation." Joan has not touched Sherlock's bed since he died. Even without Moriarty's unsubtle overtures, Joan is not getting onto or into it.

"Ah Joan. It's just for comfort. You are as broad minded as Sherlock, I know the idea doesn't offend you."

"You offend me. And the brandy is wearing off."

"Pity. And yes, it is." Moriarty wanders to the bed. She trails her hand over the covers.

"Leave it!" Joan says, in a squeak of outrage.

"Make me."

"Oh my god stop with the stupid flirting. I don't want you in his bed."

"That's the first honest thing you've said all night, darling."

"Just go, please." Joan moves to place herself between Moriarty and the bed.

Moriarty steps close to Joan. "Very well. This time I'll go. But you know you long for comfort, for remembrance, as much as I." She kisses Joan on the lips before Joan can duck, then marches out. A few moments later, the front door bangs.

Joan topples forward, a domino approaching the point of no return and teetering there, waiting for the push. But there is nobody to push her, so she lets go and falls face first onto Sherlock's bed. It smells of laundry and dust, not of him, although he did use that laundry powder for his clothes too.

She breathes. She never slept in this bed and neither did he. Why has she been treating it as a sacred object? He would think that ludicrous.

She rolls over and stretches out on her back. The pillows dig into her neck. Something is scratching her. She reaches round and her hand finds paper, a folded page lying inside the pillowcase.

A note. Watson, it says in Sherlock tight, firm script. I calculate you will find this within three days of my apparent demise. That being the case, act at once. You will need resources for the task ahead. I realise this will be distasteful to you, but if you love me, for God's sake do it. You must, I repeat must, contact Moriarty.