Sherlock was eight years old when he found Mummy still and cold in her bed, an empty bottle of pills beside her on the duvet. Mycroft was home for the summer holidays. He came running when Sherlock shrieked his name, stumbled into the doorframe at the sight of Mummy, and stood there, unmoving. Sherlock demanded an explanation.
“She’d been in a great deal of pain for years,” Mycroft finally answered in a soft, rough voice.
“She wouldn’t,” Sherlock insisted. “Not Mummy. She wouldn’t even kill the spider that was making a web under my desk.”
“Don’t be a fool, Sherlock,” Mycroft had snapped, turning away. “Everyone’s capable of this. All it takes is the right set of circumstances.”
Mycroft was correct. Circumstances had led Sherlock’s brother to become a man who dealt death at a distance; his victims were piled high on the altar of Queen and Country. He never got his hands dirty. All it took was a decisive nod; a whisper, passed from mouth to ear, ‘Who shall rid me of this troublesome priest?’ and a man’s blood would be spilled on the far side of the world.
It had become something of a hobby, over the years. Along with profession, marital status, and general habits, Sherlock would attempt to ascertain what might drive this individual to kill, and what method they would likely employ. It was an on-going thought experiment with one foot on the firm rock of deduction and the other lost in the shifting sands of probability. A game of ‘What If’ that offered Sherlock some entertainment on days when life was pale and discordant.
Mrs. Hudson was murder by poison, in self-defense. A traditional woman’s weapon, and with good reason. Her husband had a four inch, six stone advantage. Sherlock had prevented that murder by guaranteeing that Mr. Hudson died in the electric chair. Mrs. Hudson still kept a dwarf Nerium oleander plant in the corner of her kitchen. Sherlock found it charming; a deadly weapon with such lovely flowers.
Sally Donovan’s antagonism towards Sherlock had its roots in fear, ever since she’d seen what he could do. Sherlock had investigated, and found a rather intriguing incident in her past. Whilst working undercover with the drugs squad, Constable Donovan had called 999 for ‘Big Dave’, a notoriously vicious pimp and dealer. He’d been declared dead of an over-dose on scene. Sherlock believed that the man had probably injected himself. He wasn’t certain if Sally had provided the curiously pure hit that had killed him. But Sherlock had seen the way her eyes wandered speculatively up and down his frame when she confiscated a baggie of cocaine during a drugs-bust at his Montague Street flat. There was no doubt in his mind that she had watched as Big Dave collapsed, panting and convulsing, and died slowly at her feet. Big Dave had been long-dead by the time the ambulance crew arrived.
Sally worried that Sherlock might someday reveal her crime. A needless concern; he rather admired her for it. Every vaguely competent police officer was capable of murder in the cause of justice. Lestrade would certainly kill to protect his own. Sherlock thought he might also go for a child-murderer. A killer whom Lestrade knew, but could not prove, to be guilty. One that had a taste for it, and would keep on killing until someone stopped him. Sherlock had generously decided that Lestrade had the experience necessary to plan and execute the murder without giving himself away, and that the corpse would never be found.
Anderson had an entire list of people he would kill, if he could get away with it. His own wife, for the insurance money, had been at the top of Anderson’s list when Sherlock first met the man. Sherlock had managed to displace her a fortnight later by gleefully informing Anderson that he was not, in fact, intelligent enough to murder his wife without being caught, and therefore shouldn’t attempt it.
Molly Hooper was a crime of passion. A sharp-edged instrument snatched up in a moment’s rage and shoved home with a pathologist’s instinct for lethality. She would almost certainly turn herself in afterwards. Dull.
Sherlock was surrounded by people who avoided committing murder by the slimmest margin of happenstance. Yet he himself had never killed anyone.
Except for the cat. Mycroft had been appalled when he found Sherlock vivisecting it, two days after Mummy’s funeral. There had been a flurry of psychiatrists and diagnoses. Mycroft had said that if it ever happened again, ever, that he’d have Sherlock sectioned.
It’s not as if Sherlock had intended to torture the animal. He needed to see what it looked like, when something died. Only he couldn’t bear to put it to sleep first, as he’d planned. The cat surely had a right to fight for its own life, and the deep scratches on Sherlock’s face and arms distracted him from the fibrous mass of feelings in his chest that made it difficult to breathe.
It had only been the once.
He’d thought about it, certainly. When he caught a stupid killer Sherlock always considered how he might have done better. When he caught a clever one, Sherlock couldn’t help but enshrine the details of their murder in his Mind Palace, ready to be retrieved should he ever need them. After all, every other human being was capable of murder. Who’s to say he wouldn’t try his hand at it someday?
There’d been a few times, when assaulted by some despicable specimen of humanity, that Sherlock had come close. His study of Krav Maga suggested any number of potentially deadly strikes, as did his extensive knowledge of human anatomy. An elbow to the temple rather than the cheek. A forceful stomp to the neck of a man who was already down. The world would be a better place without some of them breathing the air. Rather a lot of them, actually. And that was the problem. Sherlock didn’t know, if he started, where he’d stop. ‘Thou Shalt Not Kill’ was a simple enough rule. Once broken, there were only the murky gradations of Right and Wrong. Not Sherlock’s area, at all.
By the time Sherlock determined that John Watson had served in Afghanistan, he’d identified the man’s most likely murder as a mercy-killing of a fellow soldier to avoid an otherwise inevitably long and agonizing death. Or possibly a suicide, to avoid an even longer and more agonizing life. Then there was a crime scene, a roof-top chase, a crack shot with strong moral principle who saved his life, and it turned out that Sherlock had underestimated John Watson.
John had killed for him. For him, as if Sherlock Holmes were one of those ‘loved ones’ that people would protect at all costs. And although he was clearly a good man, John didn’t suffer a moment’s remorse over it. He was apparently an expert in the field of Right and Wrong. Sherlock respected expertise, in any form, and was particularly impressed by those who had mastered some useful skill that he did not himself possess.
Still, Sherlock had failed to comprehend how truly extraordinary John was.
Sherlock had never met the victims of the cases he solved, so it was easy not to care about them. “Is that news to you?” he’d sneered at John. Even with Sherlock’s mind fully engaged by the most diverting series of crimes he’d ever seen, there was something striking about John’s tight, furious smile when he replied that it was not. Something dangerous. It took seeing John in a moment of violence, willing to kill or be killed to save him (once again) for Sherlock to put that smile into the proper context and realize that he’d discovered another murder for John to commit. And this one, this one was brilliant.
Ever since the cat, Sherlock had lived with the fear, in the back of his mind, that someday he would go wrong. He’d cross some invisible line, from useful to dangerous, and Mycroft would have him sectioned. White walls and fluorescent lights, the numbing static of antipsychotic drugs and boredom smearing him into an endless tormented stupor.
But now Sherlock knew it would never happen. That line wasn’t invisible to John. He knew exactly where it was. So while Sherlock Holmes might not have it in him to be a hero, he would never become a villain. Because John would do everything he could to keep Sherlock on the side of the angels. And if that should prove impossible, John’s smile promised to put him down like a rabid dog.
It was such a relief, to relax and trust John to do the Right Thing in this, as in all things.
Sherlock considered John’s method, should it become necessary. A shot to the back of the head, execution-style? The wrench of a broken neck? Of course, John was a doctor as well as a soldier. He had the medical knowledge to be more inventive. Perhaps Sherlock would be woken from a deep sleep by the prick of an injection, and finished off in some intimate fashion. Sherlock imagined a hand covering his nose and mouth, cutting off his breath until the world went black.
“What are you smiling about?” John asked. His chair creaked as he settled into it with a cup of tea. Earl Grey, by the pungent scent of bergamot.
“You,” Sherlock replied blissfully, eyes closed, from his position on the couch, “are the very best murderer I know.”
“Bit not good,” John chided him with affection. There was a rustle from the Sunday paper, and then all was quiet.