Sherlock had a secret.
Even he found this to be odd, for he was usually a very open person. His words were typically honest to the point of being blunt, which was one of his characteristics that others found to be offensive. But months had gone by and he had been through his share of confrontations and reunions and over time he had developed a secret; a secret that he did not want anyone to learn.
Sherlock was fairly good at keeping information to himself until he was called out. He hadn't planned on telling John about his drug problem until John asked. He hadn't intended for Irene to know the extent of his genius until she plucked it out of him with a pair of prodding tweezers. And he certainly did not intend for anyone to know about the crossroads deal – not John, and especially not the two foolish hunters.
Sherlock's knack for withholding information until a disclosure was requested or demanded, kept him from feeling immense guilt. But a secret was something different altogether. He couldn't justify it by claiming that no one had ever asked. He simply had to accept that he was being dishonest and attempt to move on, but for some reason he found this exceedingly difficult. He felt as if the secret was constantly poking the raw walls inside his head and hissing abuses into his ears. It got to the point where he would lay in bed at night, listening to Johns accusatory snores from the room over, and decide that he was not harboring a secret but a lie.
He lied to Mrs. Hudson when he told her that he would've never left her alone in 221 B. He lied to Lestrade when he said through a smirk that he had not, in fact, planned on quitting his job. He lied to the tears running down John's cheeks when he insisted that he had a plan for surviving the Reichenbach Fall since before he sat down at Moriarty's table. And he was lying to himself when he claimed that by closing that phone, he was not saying goodbye to the only friend he'd ever known.
Sherlock was lying because he was supposed to be dead.
He had planned it the day that his enemy's name escaped from a dying man's lips; he would outsmart this Moriarty and eventually use him. Use him to make everything easier, not only on himself, but on John. The Hellhounds would be too messy; they would hurt Sherlock, but they would torture John relentlessly until the day he died, and they would riddle John's existence with loose ends and clues that he simply could not string together, no matter how hard he tried.
So Sherlock made a decision. He wouldn't let the hounds kill him, and leave John buried in confusion and remorse. Sherlock would pretend to play Moriarty's game, presenting himself as the pawn that the mastermind intended him to be. He'd follow Moriarty's rules, but write his own at the same time, and allow his enemy to plan Sherlock's downfall – literally, but more importantly, figuratively. He would let Moriarty murder him so that he could leave his companion with disappointment, but a reason to live as well. By threating to end John's life, Moriarty was actually ensuring its wellbeing, as Sherlock saw it. If John watched Sherlock die as a fraud rather than an idiotic gambler of his own life, he could live the rest of his own life in peace.
Or so Sherlock assumed.
He hadn't counted on Molly Hooper to outsmart him.
Not that she knew that she was outsmarting him by using that laundry bin to break his fall and then getting him to hospital before he could die like he so desperately wanted. After she foiled his plan by nursing him to health, he made her promise not to tell anyone that he had survived. But how could she be expected keep her mouth shut after seeing what Sherlock's supposed death had done to John? So after three years, Molly gave away Sherlock's secret, and any hope that he had of leaving John with the least amount of pain.
So months passed.
Some of the best months of Sherlock's life, as Sherlock would grudgingly admit. He and John solved many crimes together and reformed their friendship piece by piece until it was taller and grander than what they'd had before Sherlock jumped. John never understood why Sherlock was always in such a hurry, to explore a crime scene, then have an interrogation, and then have dinner, all in the span of an afternoon. John didn't know that time was ticking, and if Sherlock couldn't save John, then he was personally accountable for making sure the time before he left him was the best time of John's life.
His deadline was a year.
The year became a month.
The month turned into a week.
And then it was the day of Sherlock's death and two men came knocking at his door.
He had to pretend that he didn't know what they were talking about – crossroads demons and hellhounds – but they barely seemed fooled. The shorter of the two said his name was Dean, and gave Sherlock two phone numbers, saying that if he or John 'saw anything unusual,' then they should call him or his brother Sam. Sherlock was annoyed. He hadn't intended for John to have any prior warning of Sherlock's fast approaching death; any warning would lead to an expectation of an explanation that Sherlock was not willing to fulfill.
The men showed up at Sherlock's flat again, just after Sherlock had begun to hallucinate. John had told him to lie down on the couch, and was in the process of making a kettle of tea when their door was suddenly kicked open. Dean and Sam burst into Sherlock's flat.
"You lied," Dean growled through his teeth, staring angrily at the man lying on the couch, whose arms were coated in nicotine patches.
Sherlock didn't even look up. "Please leave."
He suddenly flinched, hearing sharp barking from a few floors down. The noise seemed to be solely in his own head – or so he'd determined when everyone else in the room seemed unfazed.
"You can hear it, can't you?" Sam inquired, taking a few steps closer to the couch. "You've already started getting hallucinations I'll bet. It's only a matter of time."
"A matter of time until what?" John cut in shakily, staring at the two hunters, his expression alarmed and concerned.
"Nothing," Sherlock said sharply. "May I have that cup of tea now, John?"
John muttered something under his breath, but left the room.
Sam turned to Sherlock as soon as John was out of earshot. "You haven't told him, have you?" he asked. "Your own husband doesn't know you're going to die."
"He's not my husband," Sherlock wanted to say, but instead he grimaced at the sound of the dog barking again, this time from the stairwell.
"I don't know what you're talking about," Sherlock said.
"You made a deal with the devil," Dean shouted angrily, "A deal to make you a genius. You decided that ten years of being the smartest guy in the room, was better than a lifetime of being average like the rest of us. And now your time's running out, isn't it Sherlock? You can't impress anyone when you're dead."
Sherlock jumped to his feet, the blood pumping in his ears. "You don't know what you're talking about," he said quietly. "I made a deal, I admit it. But I did not trade my life for intelligence."
"You shouldn't trade your life for anything," John said entering the room. "What are you going on about? What are these two men doing here?"
"Unless he lets us help him, Sherlock's going to die," stated Dean simply.
John dropped the cup of tea that he was holding. It hit the wood floor with a crash and burst into pieces, spilling hot tea all over the floor."Wha- Is that true, Sherlock?"
"Very true," he admitted. "Ten years ago I made a deal. Today, I pay the price. There's nothing these fools can do to save me."
"What deal could you have possibly made that was worth your life?" John asked, with a humorless laugh.
"Not important."
The barking was getting closer now. It was making its way up the stairwell, stopping occasionally to sniff for Sherlock's scent. The men in Sherlock's living room adopted demonic faces that growled and spat like wolves. They would find him in less than a minute.
"They're here." Sherlock said quietly, breaking the silence. The men's faces returned to them.
"What the hell was the deal for, Sherlock?" Dean restated, a note of desperation in his voice.
"It doesn't matter now."
"It does matter," John insisted.
"Why?" Sherlock asked.
He didn't get an answer. Sam and Dean were suddenly knocked to the ground, invisible claws tracing bloody marks across their backs. John shouted out a curse before turning ghostly pale and flattening himself against the wall. There was a moment when all that Sherlock could hear were the hunters' pained moans and John's heavy breathing. And then, he was listening to the sound of his chest being torn into pieces.
"Sherlock!" he heard John cry, through the snarls of the dogs and his own internal screams.
"Busy!" Sherlock called, staring into the hound's evil red eyes and making deductions about the route that it had taken to get here.
"What did you trade your life for?" John demanded.
Sherlock died.
Covered in blood in the middle of his flat, in the company of three others. When he learned of Sherlock's demise, Lestrade called in every specialist that he had ever heard of to try and figure out what had happened to the world's only consulting detective. But the hunters were thorough. They made sure that the cause of Sherlock's second passing left no evidence that could prove the ordeal was anything other than a bizarre animal attack. Only three men in the entire world knew the complete truth about how Sherlock died, and only one of those men had managed to hear Sherlock's last word; an explanation for why he did what he did.
John Watson was trustworthy – Sherlock knew that for sure. John never told anyone Sherlock's answer to the question that could have haunted him for years:
"You."
