You can't really tell if something's an addiction until you try and give it up.

Hadn't someone uttered those very words to her not so long ago? Was it the Doctor? Probably. The man liked to consider himself so full of insight and inspirational quips that Clara found it a wonder he needn't walk with his head tilted back to prevent it all from spilling out.

Ah, addictions. She was content to say with unabashed pride that she had never found the need to reach for a cigarette in times of stress, and she was apt to enjoying alcohol with moderation. Her sudden separation from Jim Moriarty however, was a slightly more potent chemical, and her withdrawal symptoms could not be solved with a simple nicotine patch.

It had been three weeks and four days since she had last seen the elusive man, three weeks and three days since she had last had any form of contact with him. Needless to say, the barely perceptible tremor in her fingers as she furled her hand around the handle of her favourite mug was not due to an overdose of caffeine. Though she would admit, she had definitely been consuming more than the recommended intake of coffee for the average British woman these past few weeks. Still, she couldn't chalk her sleepless nights up to caffeine induced jitteriness. No, the consulting criminal could accept full blame for her arduous struggle with insomnia, thank you very much.

A text message. A few, simple lines of digital text was all that he had left her with, added almost as a dismissive afterthought to his downright threatening note assuring the world and its mother that everything was going to bloody burn. The Doctor had been less than pleased, and Lestrade had been getting less sleep than her, she'd wager. John Watson was still trying to claim his right to sainthood due to the strenuous amount of time and patience he had given to hauling the drunken inspector off a barstool each night and putting him to bed. Yes, the spider really did know how to worm his way under people's skin.

Dearest Clara, by the time you set your pretty little eyes upon this message I will have swallowed my SIM card, so don't try to contact me. As long as you don't succumb to the temptation of being insufferably dim like so many ordinary people, you should be able to play along with my little game without getting hurt. For your sake, I hope you can keep a tight rein on your senses, all five of them please.

All the best,

Jim x

That was what she could remember of the message at least. She had scarcely had time to read it before the mechanical components of her smartphone began to emit an increasingly insistent whine, finally powering down with a static pop. When she had managed to reboot the device, all traces of contact from Moriarty had been conveniently wiped. She was just grateful that he hadn't pulled out all the stops and programmed her phone to self-destruct. She could almost hear his soft, derisive laughter resonating off the corners in her quiet flat as he shook his head at her almost pityingly. "Now, don't go giving me grief over this, Clara. You'll appreciate these antics when the spotlight shines on my big finale. Allow me the courtesy of making it spectacular at least."

She drained the dregs of her coffee and plucked a piece of fruit from the bowl on her pristine countertop. Stress had induced in her a nonsensical urge to clean her flat from top to bottom, and she had repeated the cycle at least five times during the past few weeks. It beat waiting around aimlessly for the depraved madman to finally strike the match and unveil his big plan.

"An apple a day keeps the madness at bay," She sighed, turning the shiny product around in her hand, as if examining it from every angle of its smooth surface would somehow reveal to her the secrets of the universe. She took a bite, regretting it instantly. The fleshy fruit tasted sour and acidic, and it reminded her of Jim and the looming threat of his great game, inching ever closer. She felt like one of those poor sods in a movie running fruitlessly from a huge, ominous shadow increasing steadily in size until the object casting it finally caught up with its projection and prepared to crush them into the unforgiving ground. A ridiculous image clawed its way to the forefront of her mind of Moriarty rolling a giant apple as if it was a bowling ball, the deadly sphere careering around corners and cavorting its way through London, knocking down everything in its wake. She let out a high pitched giggle of hysteria and threw the apple away.

A knock sounded on her door and she jumped. She was becoming more and more uneasy these days, susceptible to start at the slightest sound. She was like a coiled spring, wrought tight and ready to break its bonds. Perhaps it was from spending so much time alone with her own mind. Visits from the Doctor hadn't been frequent enough since she had relayed the message to him, and all her time spent with Sherlock and John only served to rile her up more. She ought to get some sort of animal. A cat, maybe.

Shaking any self-deprecating thoughts from her subconscious, she urged her sluggish, slipper clad feet to propel her across the floor towards the door. The grating sound of her letterbox as something was pushed through resounded down the hall as she turned the corner just in time to see a brown envelope slid through the opening and fall to the floor with a soft thud. The letterbox slammed shut after it with a not-so-polite clank.

She hurried to pick it up and thrust open the door after a brief altercation with the lock- She always kept the door locked these days- but whoever had delivered the envelope must have had the stealth of a ninja because when she peered outside there wasn't a soul in sight. Huffing slightly, Clara closed the door again and turned so that her back rested against the cool surface, examining the envelope. Her heart stuttered. It was completely blank except for a large M printed in crimson, marring the brown paper rather forebodingly. She inhaled deeply, prying the envelope open with fumbling fingers.

She hissed indignantly as her thumb caught on the edge of the paper and slit her skin, a few beads of red making their appearance after an introductory moment of stinging pain. Should be able to play along with your little game without getting hurt my arse, she thought stoically.

She frowned as she peeked inside the envelope. She had been expecting some sort of letter, a piece of paper at least. But nothing of the sort protruded to greet her.

"What game are you playing, Moriarty?" She muttered in resigned frustration, shaking the package daintily. She froze when she felt something respond to the movement. There was something in there all right.

She turned the envelope upside down, tipping the contents out to where her eyes could make sense of them. Ash fluttered down onto the floor, some flakes landing softly on her outstretched palm. The light, barely noticeable smell of faint smoke reached her nostrils, like that time Sherlock had been so deep in concentration he had forgot to quench his cigarette before placing it down on the newspaper, allowing the paper a few seconds of stretching and furling in the embers before John had noticed and put it out with a scowl.

Ash. Burning. Everything burns.

Clara let the envelope fall to the ground, her hands trembling. The room was shaking- No, the room was still as a post, she was the one shivering. She closed her eyes and ran a hand over her face. A peculiar mix of dread and relief had reached some sort of strange compromise which was currently constricting her airways. For some twisted reason, she was glad to finally hear from him. He was alive, he was okay. She shouldn't have expected anything less. But on the other hand…

She patted down her pockets in a fluster, feeling the bulge of her phone and grasping it tightly. She took a few shaky breaths before dialling the best helpline in the universe.

"Yes, hello?"

"Doctor. It's me."

"Ah, hello, Me. You've caught me at rather a bad time, I'm afraid. You see, I'm being hailed by another ship-"

"Other alien civilisations can wait, Doctor, this cannot," She was surprised that her voice remained composed, even if the rest of her body seemed determined to betray her actual fear. "Can you come here? Now, preferably? And you'd best pick up Lestrade on the way, I'm sure-" Her voice cracked, and she cleared her throat hurriedly, eyeing the pile of ash on the floor. "I'm sure he'd get a real kick out of this."

"What's happened, Clara?" The Doctor's voice had switched to a more serious tone, concern permeating his words. "Is it to do with-"

"Yes," She breathed, clutching the phone tighter. "I just got a pile of ash posted to me professional as you like and I don't think it's much of a stretch to believe that this means things are going to start burning now."

"Oh bloody hell."

"I know."

"No, I mean bloody hell, the distress signal I'm picking up is from UNIT."

"UNIT?" Clara started, the blood in her veins suddenly running cold. A million possibilities coursed through her mind, all resting steadily on one chilling conclusion. "Doctor, you don't think-"

"Oh, I do," He replied gravely. "Make yourself presentable, Clara, and be ready in two minutes. UNIT HQ is on fire."