The man on the ground was dead, an empty shell that once held life. The knife still remained plunged through the heart of the victim, an instant killing blow. Sherlock bent down to examine the wound, and for once, could not find it within him to be detached.

It was John.

One of the few people he ever called his friend was now dead at his feet, Sherlock's latex-gloved hand mere inches from the man's wound. He shut his eyes, doing his best to block out the pangs of grief that threatened to overtake him.

"Uh…" he spoke more quietly than usual. "The killer was taller than the victim, probably five foot eleven, and it was premeditated." Sherlock stared at John's lifeless form. "The…the killer…"

"Sherlock, if you can't do this—"

"Of course I can do this," Sherlock snapped, leaving Lestrade feeling like a student who'd just been chewed out. "It's what I do. The identity of the victim shouldn't matter." But it does.

The mood of the room was solemn, but they were all here to do their job. Clearing his head and deciding that it wasn't worth the effort of grief, he returned to his evaluation. "It was intentional. Whoever did this meant for him to be the victim. But who'd have a grudge against—" His eyes widened with realization. "Moriarty…"

"But Moriarty's dead." Lestrade shrugged.

"I know, but he must have had associates willing to step in and finish the job." Sherlock wasn't looking at anyone but John. He couldn't.

"Well, how do you know that he was the one who was supposed to be killed?"

"The note," said Sherlock simply, holding up a crumpled piece of paper. The writing was sharp, sadistic even.

You slaughtered my friend and now I am repaying the favour.

Sherlock had, except to ascertain identity, not looked at John's face. Now he did. Terror, anguish, despair, and anger all at once graced the face of his friend. Sherlock knew John so well that the face spoke in John's own words.

"Who the hell do you think you are? I'm dying again. Sherlock isn't here to save me. He'll find you. Oh, God, help me."

As the brown eyes of John Watson stared into nothingness, Sherlock left the scene. It was as if he had a clue, an inspiration for the next step, but in reality, he just couldn't bear to witness it any more, John in that dark alley just a block away from home, a knife deep in his chest.

Sherlock had returned to Bart's as required to continue his analysis. The knife had been removed and the wound cleaned. Now one could almost imagine that he was asleep, naked. Except for the gaping hole. Sherlock was meant to be inquiring as to the details of the knife that killed him and how long it took for him to die, but he couldn't. His mind wasn't working.

"Look…um," began Molly, all too aware of the awkwardness. "I miss him too."

"He's right there, how can you miss him?" He examined the wound. "The funeral is Saturday."

Funerals bored Sherlock. He'd attended so many in various capacities, but never as the grief-stricken best friend. He looked around the room, and there were so many people he'd never met—army friends, mostly. Sarah was there, of course, as was a woman Sherlock could only figure was Harry, John's sister. John was, of course, to be buried with honors, and as the people went on and on with their boring speeches about how good of a friend he was, the time he stood up against a school bully twice his size on behalf of another child, the loyalty he showed to his regiment, suddenly Sherlock realized that he was standing at the podium and speaking.

"John was truly the best friend I have ever had. While I don't doubt that you saw him as a good man, I knew him at his very best. He saved my life. And in many ways, I saved his. I only wish I could have saved him one more time." He caught a glimpse of the open casket, John's face looking peaceful as Sherlock had never once seen it, dressed in his army uniform. "I'm sorry," he whispered, and realized that he was crying. All the emotion he didn't think he had flooded in, and now it was flowing out again through his eyes and his nose and his shuddering breaths. He did not stay for the burial, but rather placed his offering of thuja, the symbol of everlasting friendship in the coffin right then, rather than waiting for the normal time to give botanical offerings.

Weeks passed and still he had not moved from his couch. He hated that he could not think objectively as the scientist he saw himself to be. On more than one occasion he'd caught himself speaking to John, and when he realized what he was doing, the tears returned. After the tears came the exhaustion, and after the exhaustion came the mind-numbing hours staring at nothing, his mind too empty to be of any use.

The temptation of his one-time friend the needle was great, but he knew that it would do him only harm. He could not think. He had on more than one occasion been literally force-fed by Mrs. Hudson. There was nothing in his mind—it was a void. He was fairly sure that it qualified as a breakdown as even the most basic of thoughts was difficult. Knowing that he had to work out who had killed his one and only friend, he emptied his entire box of nicotine patches onto both of his arms and sat in a trance, thinking. That writing. He turned it over and over in his head, analyzing it. Sadistic. Cruel. Not psychopathic as it was clear he could show emotion. Obviously male. One of Moriarty's friends. If friends was the right term. Stockholm syndrome? Or just bosom buddies? Friendship. Loss. Anger. Pain. Who? How? The knife. Despair. Emptiness. Vengeance. Blood. Hate. Murder. Scream.

He blacked out.

When he came to in the hospital, the first thing he did was look to see if John was there. Of course not, he told himself when he remembered.

"You really should take better care of yourself."

Mycroft. Of course Mycroft would be there.

"I know you've been under a lot of strain recently, but there's no need to practically kill yourself with a drug overdose. We have been over this with cocaine, remember?"

Sherlock would have said something vicious but his throat was clamped shut from grief, dehydration, and the fear of showing either, and anyway, he couldn't think of anything. He just settled for the meanest look he could manage.

"Don't be like that, little brother. I have saved your life."

Sherlock rolled his eyes.

"You should have known better than to mix nicotine and an empty stomach."

"I…" Sherlock croaked. "I needed…"

"You needed to think. I understand. But you nearly died, Sherlock. Then who would have solved the mystery of Dr. Watson's death?"

That simple sentence, both painful and oddly inspiring, made Sherlock realize what he really needed. The next few days was spent with handwriting experts and forensics scientists visiting him. Even Anderson was amiable under the circumstances. Night and day they toiled over the mystery, eliminating suspects, adding more evidence, determined to find who'd killed John. Sherlock, notorious for not eating during a case, had consented to various intravenous nutrients, and was confined to bed.

Several times, Sherlock had to be sedated after screaming at Lestrade that they weren't working fast enough or didn't really care what happened to John's killer. He threw whatever he could get his hands on when Anderson said they didn't have enough to go on. Once he even violently attacked Donovan when she said there wasn't anything else they could do for the day. Every time he was sedated, just as the drugs kicked in, he dissolved into terrible wracking sobs that no one would have thought possible from Sherlock Holmes, self-declared sociopath. He was breaking down.

After a week of constantly working, they'd narrowed it down to three people, one of whom was the only possible person in Sherlock's mind who did it. And he wasn't going to tell the police he knew where they were.

Sherlock had been discharged from the hospital for several days, and his clarity of thought was astonishing. He'd lost his only friend and had worked out for certain who had killed him. He knew exactly what to do next.

Quickly changing into a policeman's uniform, he made his way around to a small flat in a quiet part of London. He approached the door, and, knocking on it, he stood patiently. A man with fair hair opened the door.

"Colonel Moran?" Sherlock asked, his eyes boring into the man's.

"That's right."

"I'm afraid we have some questions for you. May I come inside?"

"Certainly." Moran cautiously allowed Sherlock to come in. No sooner had he closed the door than Sherlock clamped a rag over the man's mouth and nose. Even the strong military man was no match for the detective, fuelled by anger and adrenaline. Sherlock bound the man tightly in a bedroom, dimmed the lights except for a few candles, and arranged a number of photographs around the area. Moran moaned. Sherlock had changed into a cheaper version of his more normal clothes and was now whispering in the ear of the man who was regaining consciousness.

"Doctor John Hamish Watson. Age forty-two. Unmarried. Had a girlfriend. And then you killed him," he finished, turning to face Moran in the light. "I want you to see me. I want you to know what you've done. I want to hear the scream from your lips as you die. John didn't deserve what you did to him. He was a good man. The best man I've ever known, and you plunged a knife through his heart just to get to me. Congratulations. You've gotten to me. And the best part is that I don't care if I get caught. You tore out the heart I thought I didn't have, and now, to quote your friend Moriarty, I will burn you." The frozen tone of his voice was unlike any that had been heard by anyone before. It was so cold it was like liquid nitrogen. The very power of it was painful. There was a slow drip on Moran's head.

"That's not water, Colonel, that's dripping onto your head. You probably can't feel it, but it's the strongest acid commercially available. Right now, your skull is being eaten away." Moran shut his eyes. Sherlock forced them open again, and forced him to stare at the pictures of a happy, smiling John. The acid was now beginning to accumulate and Moran could not help but scream.

"Look at him!" Sherlock shouted over the man's whimpers. "Look at what you've destroyed! He had family! He had friends! He was the perfect friend and you murdered him to exact revenge." He let go of Moran's head, knowing he would risk the acid as well if he held any longer.

"Who..?"

"My name is Sherlock Holmes," said Sherlock triumphantly. "That will be the last thing you will ever know."

Moran's blue eyes widened at the look of pure homicidal insanity in Sherlock's face. No one could imagine that look until faced with it, and he knew beyond the shadow of a doubt that he was going to kill him.

"And do you know what?" Sherlock said, the hint of excited glee in his voice. "I'm going to watch you die. And I'm going to enjoy every last minute."