Disclaimer: I own nothing. Sherlock and A Christmas Carol are the creations and properties of others. I am merely borrowing them for some festive fun.

His Own Heart Laughed

Chapter One: Of All the Good Days of the Year, Christmas Eve

Moriarty was dead, to begin with.

Sherlock Holmes had no question whatever about that. He'd been on that rooftop, after all. The amount of blood, brain matter, and skull fragmentation that had issued from his nemesis was not adequate to sustain life. Journalists and anchors alike had been abuzz with nothing but the news of "Richard Brook's" death and the strange events surrounding it.

Before Moriarty's body was cremated, Mycroft Holmes positively identified it. He was seconded by bevy of other government officials who had been party to the lengthy interrogations of the criminal when he'd been in their custody.

Molly Hooper was present at his autopsy and witnessed Mike Stamford signing his death certificate. She would have conducted the postmortem herself, but kindly Mike was worried Molly would be traumatized by the task. And though he didn't voice this concern, he was also probably concerned that there might be a conflict of interest, considering her friendship with Sherlock Holmes. Still, as she worked on another autopsy, she saw the body of Jim lying on the metal slab next to her, and had no doubt that the brown eyes and manic smile she was working hard to avoid belonged to the insane man who had so easily manipulated her all those months ago.

It is important to remember that James Moriarty was dead as doornail, or there will be no wonder to the story I am about to tell you.

Sherlock was—for all intents and purposes—dead, too. News reports of Moriarty's death it never neglected to mention the figurative and literal falls of Sherlock Holmes. Unlike the very dead Moriarty, however, Sherlock was still very much alive; robust, even. A self-imposed fake death had done little to change the personality of the man. Sure, he was a slightly humbler, sadder, raging genius, but the raging genius aspect was nothing different from before his fall.

Since that day in early June, Sherlock had focused his efforts on eliminating James Moriarty's web of cohorts and underlings (with a little help-more than a little-from Mycroft and his minons). While this had required some international travel, he found himself spending a surprising amount of time in London. He had smirked to himself dryly when it occurred to him that James Moriarty may have actually put too many of his eggs in one basket.

Whatever the case, while in London, it was easiest for Sherlock to hole up in Molly Hooper's flat. She was, after all, no social butterfly. He trusted her with his life, literally, and knew that he wouldn't be at great risk of discovery. Since a lot of his work was electronic, all Sherlock really needed was a computer, internet, and a setee that he could fling himself onto dramatically whenever the mood struck him.

Luckily, Molly had all three.

While their relationship improved after she helped him fake his death, Sherlock's default personality mode was still very much a challenge. As ever, he ran a bit hot and cold with her. While there was something different about Molly that he found himself thinking about with uncomfortable frequency as he lay on her lumpy sofa at night, he had decided it was irrelevant and distracting, something best shoved aside.

And so he continued on his quest, only sometimes mindful of trying to be a courteous houseguest. Usually, he was crabby, abrupt, and quite rude.

In other words, he was Sherlock.

Once upon a time—on Christmas Eve, no less—Sherlock Holmes sat in Molly Hooper's small lounge, doing a fancy bit of hacking on her laptop computer. He was vaguely aware of Molly rustling around in the kitchen, but he was too busy trying to complete an algorithm to pay her much mind. In kind, she had been quiet the whole day and had hardly spoken to him.

That was one thing he had come to appreciate about Molly. While she had become far more assertive and confident in the six months that he'd been using her flat as his command center, she was still the kind, patient woman she'd always been. Though she was never cowed anymore, she was courteous. Well, except in matters concerning her infernal cat, who was currently draped across Sherlock's forearms as the latter tried to type. There, Molly had a bit of a blind spot, and Sherlock could never convince her that she should address the feline's obvious personality flaws. But he was coming to realize he might have plenty of time to help her reach this epiphany; he felt like the work required to dismantle Moriarty's mousetrap would never end.

As he tried jostling the cat off of his wrists, Molly emerged from her small kitchen. She was a mess. She wore an apron that had vestiges of various baking ingredients smeared across it, and there was a smudge of either cocaine or confectioner's sugar on her cheek.

She looked strangely endearing.

It was only as he glanced at her that Sherlock noticed the definite scent of warm biscuits in the air. His stomach gave a plaintive groan and he actually felt his nose twitching as he suddenly registered that, yes, he would like some food. But it was important to be subtle. It wouldn't do to appear too eager. While he was the master of ennui, he still had to practice his art. So, he casually turned his full attention on Molly, taking another subtle sniff of the intoxicating aroma that had followed her out of the kitchen.

"What's the racket in the kitchen about, Molly?" he asked, carefully contorting his cat-pinned hands to save his work on the computer.

Molly arched an eyebrow, but decided to humor him. "I'm not sure if there is one specific 'racket' you're referring to, but I've been in there doing some holiday baking. Not exactly quiet work."

This gave Sherlock pause. He worked his cursor to hover over the timestamp on the computer screen, suddenly unsure of the day. "It's the twenty-fourth of December," he said, dumbly, in his opinion.

"That it is. I was feeling festive and decided to make a batch of Linzer biscuits. I was actually wondering if you could tell me where the currant jam is? I need it for the filling."

"I finished the jar yesterday. Why are you feeling festive?" He felt his brow furrowing in genuine confusion.

Molly stared back at Sherlock, a perplexed look of her own crossing her face. "Why wouldn't I feel festive? Tomorrow's Christmas, after all."

Sherlock knew, of course, that Molly participated in the seasonal tripe that seemed to plague a good portion of the population. She'd been to his old Baker Street flat once for one such party. But he was having a hard time reconciling the way his life was effectively on pause while she continued to observe the calendar and all of those holidays that were printed in the little date squares.

Moreover, he was confused as to why she would want to.

"Molly, you have always said that your faith is in science. That you're an atheist, or at least an agnostic. Why do you participate in a day that, while it was once a pagan holiday, is now considered a Christian one and a materialistic, commercial one at that?"

Blinking at him, Molly remained quiet for several seconds before she finally spoke. "Just because I don't believe in God doesn't mean I can't appreciate the holiday. I love the anticipation. Not just for gifts, though those can be nice, of course. It's a lovely celebration. It would be nice if I believed the first Christmas story to be true, but I don't think it's necessary to believe in order to find beauty in a holiday that is about family and goodness."

There had been a few times in his thirty-some years that Sherlock Holmes had surprised even himself with a bit of forethought before he said something "a bit not good," to quote his best friend.

This was not one of those times.

"But… you don't have any family. So why do you care?"

The change in Molly was palpable, even before he finished that final, damning word. He had noted that she had grown quieter in the past few days, but he hadn't tried to deduce why and now he wished he had.

Her hands, which she'd been absently rubbing together while they talked, dropped heavily to her sides. She was quiet for a moment before she finally started speaking, her eyes getting a glassy sheen that she desperately tried to disguise by looking down as she untied her apron."I… I guess that isn't important. That is to say, I still like it. My reasons are my own. I have to do a few things in my room. I'll talk to you later."

With that, she turned and headed down the hall, her cat leaping off of Sherlock's lap to follow her. The softly closing bedroom door might has well have been slammed shut, since its noise carried reverberated through suddenly quiet flat.

Sherlock closed the laptop and set it on the low table in front of the sofa. Pulling his feet up onto the couch, he lay back, steepling his fingers under his chin.

He knew he owed Molly an apology. He had never been good at issuing them, though. So that would take some thought and planning. But more than the contrition he felt, his thoughts were mostly occupied with the looped image of just how devastated Molly had looked as soon as the words left his mouth.

And for the life of him, Sherlock couldn't figure why it bothered him so much.

He came out of his meditative state a couple of hours later when he heard Molly's door buzzer sounding. No sounds or movement came from Molly's room, but Sherlock was certain the chime had gone off. Curious that someone would be calling on his flatmate at—glancing at his watch—eleven o'clock at night, he wandered over to the little video screen/intercom that served as an electric doorman for the building's front entry.

There was nothing particularly special about the door buzzer—a visitor entered the building that housed eight flats and came to a second, locked door. If the person did not have a key, he would simply press a button that corresponded with his destination flat. Assuming the tenant was home, the person in the flat could screen who was pushing the buzzer, then push a button that temporarily released the lock, allowing the visitor to enter. It seemed to function well enough (he'd been in buildings where the landlords had let such devices fall into disrepair), though sometimes the buzzer interrupted his deep bouts of concentration. Such as now.

Expecting to see a drunken neighbor or a confused food delivery person, Sherlock did not properly brace himself for what met him when he looked at the intercom's video feed.

James Moriarty.

His face filled the screen for just a moment. Sherlock reeled back nearly to the other side of the room, but when he threw himself back to the screen, it was black. He frantically pulled up the video feed again, but all that the screen showed was an empty foyer, the lights of cars passing out on the street fractured in the poor video resolution.

Taking no time to puzzle it out any further, Sherlock grabbed the pistol that he'd stashed under the sofa (Molly hated guns and her cat couldn't paw that far under the couch) and threw open the flat's front door.

An empty, quiet hallway greeted him. He quickly looked both ways before rushing through the hall and running down the stairs to the ground floor. He passed no one on the way, nor did he hear any noise from above. The foyer looked much as it had when he'd rechecked the video feed: empty and silent.

Feeling frantic (an unusual feeling for him), Sherlock ran back up the stairs to Molly's flat, suddenly afraid as it dawned on him that he'd left her alone in his rush. He could have just fallen into a trap. He burst through her bedroom door, wild-eyed, expecting to see Jim Moriarty standing over her, or worse. Instead, all he saw was her huddled form in the middle of her bed and the gleam of the cat's eyes as they caught the light from the hallway. The only sounds Sherlock could detect were Molly's quiet, even breathing and the thudding of his own heart.

Not caring if he woke her, he flicked on the overhead light. The only reaction Molly gave to this was a mumbled complaint before she rolled onto her stomach, burrowing further into her blankets. She didn't even stir as Sherlock prowled around her room, looking behind her curtains, peering in her closet, and (though he felt a bit foolish doing so) crawling around on his hands and knees to check under her bed.

Once he had thoroughly checked the rest of her flat and then gone to the upper floors of the building, Sherlock once returned to the ground floor, but found it unchanged. He could only assume that had had somehow dreamt the whole ordeal.

Anything else was impossible. Moriarty was dead.

Returning to Molly's lounge, Sherlock once again took up his spot on her settee. Feeling too restless to even think of resting or sleeping, he reached for Molly's computer, intending to continue with his work from earlier that evening. He had barely begun typing when a rustling noise reached him. He looked up, ready to scold the cat for getting into something he oughtn't, but instead felt the words dry up on his tongue.

Sitting across from him in a hideous armchair that Sherlock usually avoided even dignifying with a glance, sat James Moriarty, idly peeling an apple with a knife.

But… not really. This Moriarty was decidedly less… solid than the Moriarty Sherlock had known. In fact, he could see the ugly puce and green plaid of the chair's upholstery right through Jim's torso, legs, and head.

Though he could remember on one hand the times he had felt genuinely gobsmacked, this took the cake. Sherlock was a man of science. A man of logic. Of philosophical reasoning. There was no earthly explanation as to why or, more importantly, how James Moriarty was sitting there, let alone a ghostly James Moriarty.

Deciding this must be some vestigial reaction to his previous drug use (more than a decade ago, but that was just a detail), Sherlock rallied himself enough to speak, to talk himself through this episode.

"If you mean to scare me, I know you're not real, so you've failed. You might as well flit away now."

The ghostly Moriarty lifted his eyes from the apple, a smirk twisting his mouth. "Oh, my dear, I'm afraid I'm very much real. What reason would you have to hallucinate me?"

"You aren't real. You're likely a specter of an exhausted brain; a daydream. Because trying to foil you, even in death, is my only waking thought. Really, there's more of aggravation than of grave about you. I'm not some shill, so I won't be buying into it. Good evening."

On this pronouncement, Sherlock looked down to the computer and began typing furiously. When he hazarded to glance back up, Moriarty was gone. Sadly, his respite was short-lived, as, in the blink of an eye, Moriarty rematerialized, this time seated directly beside him.

Slamming the laptop shut, Sherlock returned his full attention to the ghostly figure, which seemed to be having trouble remaining on the sofa and not sinking through the cushions and settee frame. "James Moriarty died six months ago. I was with him when it happened. Whatever this is," he waved his hand with a wild flourish to indicate all of Moriarty, "is not that man. There was no way to fake those injuries."

Moriarty rolled his eyes theatrically before replying. "Of course I'm dead, Stupid. I was good, but I was never so good as to remove the back of my skull and my brain temporarily."

"Then you admit that you're not real. Glad we're in accord. You can leave now."

The ghost had the audacity to chuckle at Sherlock. "Just because I'm dead doesn't mean I'm not real," and off Sherlock's sardonic expression, "Oh, don't give me that look. Even though you've never encountered something you can't explain, that doesn't mean that everything in the world has an explanation. Why don't you ask me why I'm here?"

"Make me."

Moriarty actually sighed. "Don't be such a damn child. But I'll just tell you. I'm here for your heart. The one I promised to burn out of you? Turns out if you want any kind of eternal rest or whatever rot it is, you have to spend your time alive walking amid humans, or you'll just be forced to do so after death, instead."

As he spoke, Moriarty began fidgeting with the cuff of his suit's sleeve. What Sherlock had failed to notice in his earlier shock and denial suddenly struck him.

"Hang on… is that a Debenhams suit?!"

Sherlock said "Debenhams" the same way someone else might say "Contagious Leper's".

Though he looked momentarily outraged that Sherlock had noticed, the ghost shrugged and explained, "These are the clothes I sewed in life, thread by thread, cheap button by cheap button. Each synthetic fiber weighs me down here in my eternal damnation. That is why I have appeared before you, Sherlock Holmes."

"To save me from spending my eternal days in a non-bespoke suit? I think the fact that I'm not a mass-murdering psychopath will at least rank me something by Brooks Brothers."

"No, you're completely missing the point, as usual. You wear such a suit yourself because you, too, could go to the grave with crippling regret. While you made some headway this year as far as upping your thread count, you've backslid. You've replaced one potential regret with another."

Sherlock tried to puzzle this out, but could only draw a blank. "And how do you propose to school me in the error of my ways? You hate me, so why would I have any reason to trust you?"

"Well, since you don't even believe any of this is real, what have you got to lose? Regarding your first question, I won't be doing any of the schooling. Consider me the benevolent headmaster.

"I'm only here to tell you that you have an opportunity to find the happiness, banal as it is, that I never had. But the proviso is that you only have three nights to accomplish it. So, good luck!"

On this pronouncement, he started to dematerialize.

"Wait!" Sherlock interjected, "How am I a supposed to accomplish this completely imaginary, hallucinated task?"

Moriarty returned to his full (or full for a ghost) corporeality. "Oh, did I not mention? That was clumsy of me. You will be visited by three spirits in three nights. They will show you your folly. It will be up to you whether or not you change. I'm thinking you will, because—as I've mentioned before—you're really quite ordinary."

He grabbed Sherlock's mobile and quickly pulled up the alarm clock application. He continued speaking as he programmed something in.

"After this, I really must dash. Expect the first spirit when the iPhone chimes one." With a theatric press of the 'Save' button, he smiled maniacally at Sherlock and exclaimed, "Bye!"

And with that, Jim Moriarty disappeared.

The mobile dropped into Sherlock's lap. He quickly scooped it up, expecting it to prove once and for all that the past fifteen minutes had not occurred. Sadly, he was disappointed. There, on the mobile's screen, was an alarm set for 1:00 AM, 25 December. The ringtone Moriarty had selected was one that Sherlock hadn't previously had in his phone's library, a "For Whom the Bell Tolls," by a group called Metallica.

He gazed at the phone for a moment before rolling his eyes and deleting the alarm.

"Psh," Sherlock said to no one, "Rubbish!"

But even as he spoke, he felt his eyes getting heavy. He arranged himself more comfortably on the sofa and sank into a dreamless sleep.

He was startled awake not long after to the tinny clashing of drums and guitars, as the alarm on his phone sounded loudly.

Suddenly, a blinding white light filled Molly Hooper's small lounge.

Author's note: While on a long car trip this last weekend, I listened to Patrick Stewart's recording of A Christmas Carol. As I drove along, thinking to myself that I'd really be okay if Tiny Tim kicked the bucket (did I mention that I'm a horrible person?), this story occurred to me. Sorry about that.

This is my first attempt at a multi-chapter fic. I am hoping to have the next chapter up this weekend sometime.

The title and summary are excerpts from Charles Dickens' A Christmas Carol.

Please review with any questions, comments, and suggestions! I appreciate any and all feedback!