It was just four weeks until Mary's due date and John knew that there was a problem.

The problem was not with Mary, or the baby; they were fine, even when John had told Mary he'd have to be away unexpectedly for a few days. The problem was Sherlock. As Mary's pregnancy had progressed Sherlock had become defensive and withdrawn, and today John had discovered that Sherlock had just smoked three cigarettes.

Not a disaster in the scheme of things, but a symptom John was loath to ignore.

John had been keeping a count of the contents of the slipper ever since he'd discovered it. Every now and then, when there was a case that had been baffling Sherlock for too long, or when Donovan had said something particularly cruel to Sherlock, or when there was no case at all, John would count, and there would be one less cigarette in the slipper.

However, today it wasn't just one.

Three cigarettes gone.

Only three remaining.

"Are you sure you're OK?" He asked Sherlock again, as he stood in 221B, with his bags, on his way to the station. Sherlock was visibly riled this time, and John didn't have time to press the issue.

John went to pick his phone up from where it had been on charge, but Sherlock had apparently unplugged John's phone in order to plug in his own in. John needed a phone in case Mary went into labour, but his battery was completely dead.

Sherlock's was fully charged. John was running late.

It was with strong reservations that John took the tube to Paddington for his connection.

…

Sherlock stood watching the clock with a fluttering feeling in his stomach. He'd been desperate for some head-space lately, after all the baby talk. But now that John wasn't there, Sherlock felt a twinge of nerves as he knew that, without John, he was a ship without a rudder.

The minute hand ticked round until it got to the 3, indicating that John's train was leaving, and Sherlock knew he was completely on his own.

In a daze he swept some of the clutter from the table to one side and then started to unload the contents of his coat pockets into the space.

Packets.

Needles.

Earlier that week John had told Sherlock that he was going to be away for a while, and the thoughts in Sherlock's mind had quickly darkened. He would be on his own for a long time. He was going to be... bored.

Very bored.

He needed something to make the time more interesting. He needed supplies. Not that he was intending to use them. It would simply be good to have them there.

Just to give himself a challenge.

Just to give himself something to think about while John was away.

Having the supplies there was comforting, like an old friend. And exciting. It would be interesting to see how strong his will-power was now. It must be strong, he thought. It had been so long since he had done anything.

So long.

So while John had been at 221B counting the contents of Sherlock's slipper, Sherlock had been visiting the chemist, holding a shadowy meeting with one of his homeless network, and slipping the items deftly into the generous pockets of his coat.

…

Back at 221B, Sherlock emptied the contents of his slipper onto the table next to the other supplies. He was surprised just how few cigarettes he had left.

Sherlock laid his cigarettes out on the table in a row, and one of the syringes next to them.

Three cigarettes, one needle.

Sherlock parked his mind in that neutral, dissociated space that he reserved for those times when he knew he was going to be on his own for a while. It was going to be an interesting evening.

Sherlock lit the first cigarette.

…

Moriarty studied the figure in front of him with hatred and fascination. The woman's arms and legs were bound to the chair with gaffer tape.

But there was something wrong with the picture.

Mary Watson: she looked uncomfortable and put out, but she didn't look afraid, and Moriarty was not expecting that. He was expecting Mary Watson to be ordinary; like John or anyone else. She should be crying; pleading and terrified; but instead she looked... actually she looked furious.

Moriarty couldn't have asked for anything better. This was going to be more fun than he had imagined.

Just trying to have some fun.

"You better hope Sherlock gets here soon", Moriarty purred at Mary, disdainfully.

As he spoke he laid three cigarettes out on the desk between him and Mary.

Mary regarded him coolly, giving nothing away. "What do you want?" She spat, not without a little disdain herself.

Moriarty smiled at her gleefully.

"What do I want? Well, not you, anyway", he said dismissively, "You're not important. But I think you know that. You're just a means to an end."

Moriarty paused to compose a text. He pressed the send button dramatically, shooting Mary a satisfied smile. "Well, that should bring him running along; running to save the damsel in distress."

Moriarty got up and slowly walked around Mary's chair, drinking her in from every angle. He was impeccably dressed, his expression flickering unprompted between intense darkness and amusement.

"Well", he said, "since you're here, how about a little game while we're waiting?" He put his face really close to her hair and whispered "I like games."

"I don't really feel like playing", Mary replied dismissively.

"Oh, you don't have a choice.

"You know, Mary Watson. I can torture you. I can do anything I like to you. And I would like to", he said, his face close to hers. "I could crush you right now, Mary Watson, but that would be too EASY. I could SKIN you, and your ordinary husband, and your ordinary baby. But the trouble is... once I start, it might be hard to stop." he whispered the next bit into her ear. "And these are meant for Sherlock, really."

Moriarty returned to his place in front of her now, toying with a little white box that he had pulled from his trouser pocket. Slowly he slid a small rectangular object from the box and held it in his palm where Mary could see it, returning the box to his pocket with his other hand.

Taking his time, he unwrapped the object and held it between his thumb and finger on the blunt sides of the rectangle, admiring the shine and the jagged pattern of the gap in the middle. Then he placed it on the desk next to the cigarettes.

Three cigarettes. One razor blade.

"You better hope Sherlock gets here soon", Moriarty's eyes were pools of chaotic darkness as he spoke with no trace of amusement now. "…because I have cigarettes. And I have razor blades. But I'm running out of cigarettes. And…" he added slowly "...I get So. Very. Bored."

He gave her a wide shark-like smile and picked up the first cigarette, striking a match and watching the flare settle before lighting it.

Moriarty held the cigarette in one hand, and the still-lit match aloft in the other, letting the flame burn down and down to his fingers, the light glinting in his eyes as the flame approached his skin. Finally, only when the heat seemed impossibly close, did he blow the flame out.

Moriarty took a leisurely inhale of his cigarette before blowing the smoke luxuriously in Mary's direction.

"It's going to be an interesting evening", he said, with menace.