A/N: Sonofagun I am on a ROLL this week. I've finished 3 works-in-progress just since Thanksgiving. I started this almost two years ago and I've just finished it. I hope you guys like this one, cuz I had a fucking ball writing it.

Sherlock had been in hiding for almost a year when he first started believing in the supernatural.

After his 'death' he had flown to America to find Irene. Only to find her truly dead. She had been shredded to ribbons by enormous animal claws - in her apartment in the middle of the city. He arrived a couple of hours after she had been found. Apparently he looked suspicious enough for the authorities - that Sherlock could easily tell weren't really authorities at all - to pull him aside and question him.

Sherlock had called them out immediately and demanded to know what actually happened. With a few more condescending remarks and a jab at the shorter one's ego he got his answer: Hellhounds. A day of research and another of secretly following the brothers - for they were brothers, he could tell, even if they didn't look much alike - Sherlock discovered that Irene had made a deal with a demon 10 years previous. What the deal was for was unclear, but Sherlock thought he had an idea.

A month later Sherlock and the Winchesters parted ways as good friends. The brothers knew about Sherlock's past consulting, as well as his faked death. He learned about how they got into hunting and many of the basics.

On the second anniversary of his 'death' he went to his gravesite to see if John still visited; he did. John told him he was getting married soon, that he wished Sherlock were there to see it. A moment of silence and he turned and walked away.

He had taken down Moriarty's henchmen. Surely two years was long enough for the hype to die down.

He followed John around a corner and came to a halt. His heart stopped at the sight.

John was on the ground and the car that hit him was speeding around the corner.

"JOHN!" Sherlock ran to his friend and rolled him onto his back. His eyes fluttered open. "Sherlo-" he coughed.

"No John, don't speak," Sherlock said, cradling John's bleeding head. His pulse was thready and breathing shallow. He was fading quickly. "John, hold on. I came back. I came back for you." Sherlock could hear a woman calling an ambulance.

John was declared dead upon arriving at the hospital.

That night Sherlock did something he never thought he would be desperate enough to do: He summoned a crossroads demon.

"Hello, Sherlock."

Sherlock's blood ran cold. He had heard that voice before. But it was impossible. Rather, it was the most improbable circumstance anyone could ever imagine.

He turned and his eyes confirmed what his ears had told him.

Jim Moriarty stood in the middle of the intersection dressed impeccably in his trademark Westwood.

"Surprised to see me?" he asked, a smirk on his lips. "I understand. I felt the same way when I heard you had faked your death and went to America." Jim took a few steps closer and held up a finger. "I was even more surprised to learn that you had befriended the infamous Winchesters and started hunting."

"Moriarty," Sherlock whispered.

"Yes." The demon's eyes flickered black then back to their familiar whiskey. "Crowley told me everything, Sherlock. And I've been watching you ever since. I know what you're here for. That's why I came, myself."

"Give John back to me," Sherlock muttered, voice shaking. "And you can have my soul in ten years."

Jim smiled a shark's grin and laughed. "Oh no, Sherlock. You weasled out of our last bargain. How do I know you won't try to get out of this one?"

Sherlock tried to swallow, but his throat was too dry. He was desperate. "Because I need John. Eight years."

Jim's smile never faded as he took a few more steps forward. "No wonder the Winchesters took a liking to you. You're just like them. Neither could live without the other. You know Dean made a deal for his little Sammy? Just like you are for John." Another step. "Dean got a year to live."

He was finally close enough to Sherlock that he had to look up at his face. "I'll do you one better. I'll give you two. Two more years with dear John. And then you're mine." He laid his hand on Sherlock's ever-present blue scarf and waited for an answer. He knew how desperate Sherlock was, and he knew he had his soul in the bag.

"'Prepared to do what ordinary people won't do,'" Sherlock whispered, quoting himself. "'If you want me to shake hands with you in Hell...I shall not disappoint you.'"

"Perfect." Jim clutched the scarf and tugged until Sherlock's lips crashed onto his.

Thirty minutes later Sherlock stood at the foot of John's bed and watched his eyes open. He smiled, barely holding in his tears of relief.

"Hello, John," he greeted. "It's good to see you again."

John felt groggy and his head hurt, but otherwise felt alright. He gazed at Sherlock as if he were a ghost - or an angel. "Am I dead? Did that car kill me? Is that why I'm seeing you?"

Sherlock's smile shook, but held. "No, John. You lost a bit of blood when your head hit the pavement, and you passed out, but otherwise you're fine. The Doctor's say it's quite a miracle."

~*DD*~*DD*~*DD*~

Almost two years later, nearly four years since meeting him, Dean got a call from Sherlock Holmes.

He and Sam were just celebrating a quick and easy kill. They didn't have many, so they tended to appreciate them. Dean was appropriately cheerful. "Hey, Sherly, haven't heard from you in a while. Must not be many monsters on that island o' yours, huh?"

"Not as many as one would think, but there are some. Which is why I'm calling. Can you fly to London? I need your specific...assistance with a particularly troubling situation."

"Well, we just finished up a case here, so we don't really have anything goin' on. As long as you're payin' for everything else we can get the transportation." By which he meant he'd have Cas fly them, 'cause Cas doesn't crash like planes do.

"Very well. I suspect the situation will be resolved fairly quickly once you've arrived. I'll tell you more later."

The call disconnected and Dean finished the last bite of his burger, then a drink of his beer to wash it down. "Pack it up, Sammy, we're goin to London tomorrow."

"Sherlock, huh?" he asked, having heard Dean's half of the call. "Did he say what he was hunting?"

Dean got up and threw the fast food wrappers in the trash. "Nah. Said he'd fill us in when we got there, but I got a feelin it's demonic. No one ever asks us to help with a routine haunting. It's always freakin demons, man." He closed his eyes and basically continued in the same voice, "Cas! Hey, whenever you're not busy we need a ride to Sherlock's place in London. Like tomorrow."

~*DD*~*DD*~*DD*~

He didn't know how they did it, but Sam and Dean were standing in Sherlock's apartment the next day with two backpacks each. Presumably one held clothing while the other had various hunting paraphernalia.

Suddenly a man in a trench coat appeared next to Dean. "The building is secure against demons. The car is outside."

"Sherlock," Dean greeted. "This is Castiel. He's an angel."

"Dean's afraid of flying so Cas flew us here," Sam smirked.

"Planes crash! Angels don't!"

"We didn't fly here," Cas corrected. "I used my power to transport us here. You would not be able to survive flying with me, as I would have to be in my true form."

"True form?" Sherlock probed.

Cas nodded. "Angels inhabit a vessel much like demons, but we require permission from our hosts. Some angels strive to return their vessels in better condition than before, while others who don't care for humanity simply don't bother." He paused, then added as an afterthought, "My true form is approximately the size of the Christler building."

"Interesting. Now to business. Have a seat." Sherlock leaned on the arm of his chair and crossed his ankles while the brothers and angel sat on the couch.

"What do you know of James Moriarty?" he asked them.

Sam and Dean shook their heads. They only knew that he was an enemy of Sherlock's, but Cas looked intrigued. "I have heard Crowley speak of him, but I admit I don't know much myself. He is a high level crossroads demon much like Crowley was before he declared himself King of Hell. It was said Moriarty was Crowley's second in command and took over as "King of the Crossroads."" His use of finger quotes amused Sam, Dean merely rolled his eyes.

Sherlock nodded. It made sense. "He was also my criminal equivalent before I knew he was a demon. I'm a consulting detective. I solve crimes other can't. He was a consulting criminal. People hired him to carry out their crimes for them. He's the person responsible for my faking my death.

"He's come back and I'm going after him. I would appreciate your help."

Dean stood from his somewhat awkward seat on the couch and cleared his throat.

"Awesome," he said, more for something to say than an actual sentiment. "But first things first. I can't work without food and sleep. I can't speak for these guys, but there's somethin' about bein zapped halfway across the world that leaves me starving."

That night Dean slept in John's old room, Sam took Sherlock's, and Cas watched them, invisible so as to not make them uncomfortable. Sherlock stayed in the sitting room and played his violin softly. The song was inspired by John, written for him, really, but he never mentioned it, only ever played it as background music for thinking.

And he planned.