The sky was grey, clouded over, and the gaps were just beginning to fade into the deep blue that followed sunset. It should have been beautiful, but it wasn't because Greg knew the clouds wouldn't be content with hanging over the streetlamps. It was going to be one of those hideously close, foggy nights when not a single star pushed through the cloud layer and the damp crawled down your neck and beneath your coat collar. It was one of those nights that people who didn't live in London loved to romanticize, right along with the echo of hooves and hansom cabs on cobblestone streets. Lestrade snorted as he slammed his car door, hunching further into his jacket. The eighteenth century could keep the fog, as far as he was concerned.

He looked up at the brick building in front of him and sighed. Sherlock wasn't going to be happy to see him.

Not feeling well. Don't bother me. SH

Right.

Greg knew full well that Sherlock's text contained less truth than his brother's job description. Sherlock Holmes didn't get sick. The man was a bloody automaton. In the ten years Lestrade had known him, he'd never seen Sherlock come down with so much as a cold. He even recovered from injuries at a freakish rate.

There was no way Sherlock Holmes was ill. There had to be another explanation. Petulance. Boredom. Something.

It was the Something that had Greg worried.

Lestrade was at his wit's end. The police had hit a handful of dead ends on what Sherlock would have called a magnificent series of burglaries. He ought to be over the moon over this, Greg thought, glancing wryly upward at the round, pale coin that shone silver through the mist. Yet the detective had maintained determined radio silence in spite of two calls and half a dozen increasingly desperate text messages. Something was up. The only time he'd done this before had been…

A long time ago.

Not feeling well. Don't bother me.

Lestrade glanced down at the bulge his phone made in his jacket pocket, his heart sinking. There was a number listed with no contact name. One he'd only had to call once before, and really, really hoped never to again.

First things first. Greg squared his shoulders, sighed, and tapped lightly on the door marked 221B.

John had curled up next to Sherlock on the sofa.

This was, contrary to Mrs. Hudson's belief, not an ordinary occurrence.

Actually, there was a lot about the scene that was out of the ordinary. Cuddling didn't really scratch the surface.

Sherlock heard the knock downstairs but disregarded it. The lightness of the sound and Mrs. Hudson's fluttering pointed to the probability that it was a friend of hers, one she hadn't seen in a while. No one visited 221B except for clients and occasionally Lestrade. He had already made it clear that Lestrade wasn't welcome, and though Sherlock had had late-night clients before, they nearly always rang. When they did knock, desperation spoke clearly in the force of knuckles against wood. It was seven o'clock, late for working hours but not too late for a social visit. And Sherlock didn't receive social visits.

Which, on this particular night, was just as well.

Sherlock, lounging on the sofa, remained relaxed in this assumption for a few blissful moments, until the murmur from downstairs resolved abruptly into Lestrade's familiar, booted tread ascending the stairs.

Sherlock cursed under his breath. Once in a great while the balance of probability let him down.

Of course Lestrade would choose this night to be a meddling idiot. There wasn't even time to head him off. But that was all right, because on nights like this, John always locked the door.

As the steps leveled off at the landing, John jolted into consciousness and gave him a Look. If it had been anyone else Sherlock would have called it raw, unrestrained panic.

He froze. "Oh, for Merlin's…"

The door was flung wide before either of them had time to move. Sherlock was opening his mouth, whether to curse or to berate the detective inspector he hardly knew—but if it was the former, Lestrade beat him to it. Quite colorfully. With much melodramatic stumbling against the doorframe.

Recovering swiftly and deciding the quickest thing was to wait it out, Sherlock leaned back and stifled a yawn.

"What—what is that thing?" Lestrade stuttered, eventually realizing that the Thing was not leaping up to eat him.

"Really Lestrade, I should think…"

"No," Greg interrupted. "Rephrased: what is a bloody great wolf doing on your sofa?"

Sherlock looked down. His flatmate looked as offended as it is possible for a werewolf to look while trying very hard not to raise his hackles, growl, eat anyone, or otherwise indicate displeasure. Through the sofa cushions, however, Sherlock could feel the thump of John's enormous heart hammering inside his ribcage.

"Blindingly inaccurate deduction, even for you, George." Sherlock ran a hand over John's thick ruff, partly for show, mainly to reassure him. John's transformation had rendered him, intriguingly, more responsive to physical touch than verbal assurances. Like any other canine.

"Toby is a wolfhound. Obviously. I'm looking after him…for a friend."

"You're not telling me that that enormous…thing…is just a dog."

"That's precisely what I'm telling you," retorted Sherlock. "Honestly, Gavin, just because you and your soon-to-be ex-wife prefer useless, yappy things along the line of Yorkshire terriers…"

"It's Greg, and Smokey belongs to my wife, for your…" Lestrade shook his head. "You're sure it's not going to rip me apart?"

Sherlock stroked the wolf's ears, considering.

"He has no such intentions, though I might," he snarled at last. "Didn't I tell you not to bother me? Are you going to explain why you have a right to barge into my home?"

Lestrade shifted uncomfortably.

"Mrs. Hudson…" he began.

"…has no right to invite you into my flat without knocking," Sherlock interrupted.

Sherlock was right, of course. Lestrade hesitated, leaning against the doorframe, but it didn't take long to make up his mind. 'Toby's' shoulders tensed as the detective inspector stepped inside the flat, the door slamming shut behind him.

"May I sit down?" Lestrade asked with exaggerated politeness, eyes still fixed cautiously on the wolf.

Sherlock lifted his chin.

"Interesting."

Greg forgot about politeness, exaggerated or otherwise, and settled himself in an armchair with his feet braced against the floor, prepared to fling himself to the side if 'Toby' decided to pounce.

"What's interesting?" he asked guardedly.

"You are. If I had bothered to check my phone, the last few texts would showcase your increasing desperation for help with a case that anyone, save perhaps Anderson, could solve if they just applied their brains…at first I presumed that was why you were here. Perhaps it was, in part. But the reluctance of your knock downstairs reveals your trepidation. You don't want to be here. Or, you hoped I wouldn't anticipate your presence. Or both."

Sherlock continued oblivious to Lestrade's attempts at interruption, steepling his fingers under his chin.

"You were in a rush, that much is obvious, but as you are ordinarily complacent beneath the crushing burden of society's constraints, flinging open the door to my flat without knocking is out of character. Showing your hand. It's not just the case, then…oh, dull." He closed his eyes. "You wanted me caught by surprise. Hoping to catch me 'in the act'?"

Lestrade rubbed his hands over his face.

"Not hoping," he said wearily. "Never hoping."

Sherlock sat up, pushing John's head gently onto his knee. It was something of a shock to hear Lestrade's sincerity echoed in his own voice.

"Greg. I'm not on drugs."

Lestrade raised his head, searching Sherlock's face. Finally he sighed. Leather squeaked as he shifted in his armchair.

"I want to believe you. You've no idea how badly I want to. But—"

"You just assume I'm lying?"

"It wouldn't be the first time," said Greg acidly.

"I've been clean for ten years," Sherlock's razor voice stopped him cold. "More or less. Besides which, there is no reason…I have cases. I have work. I am perfectly fine."

"You were," Lestrade broke in. "You were. I don't know anymore."

A dangerous edge crept into Sherlock's voice. "Why is it any of your concern?"

"Why did you lie about being ill?" Greg countered.

"I was busy, Lestrade!" Sherlock snapped. "With another case. Do you think I have nothing better to do than wait for you to come crawling…"

"Oh? Has that case lasted two months?"

Sherlock recoiled.

"I caught you several murderers within that time period, as I recall." His voice was granite.

"Yes, but you've…"

"You're welcome, by the way."

"Yes, you've helped!" Lestrade shouted. "Bloody magician, you are. It's been business as usual, except you've hardly said a word."

"The likes of Anderson and Donovan aren't worth—"

"In two months."

The wolf raised its head. Sherlock's hand stilled on its ruff, tightening slightly. His own pulse was beginning to race now. He'd thought he'd eliminated the necessity of having to Obliviate Lestrade with his clever, quick thinking and lies, but the man was making it so bloody tempting…

Lestrade was still talking, oblivious to his danger.

"You're miserable, Sherlock, it's obvious, and you have been since…I know where that leads, or at least where it's lead before. And I can't let you go there."

Forget obliviate, other curses were racing through Sherlock's mind now, and though his wand lay inanimate beneath the sofa, he had to curl his fingers tightly in John's fur to keep them from leaping out of his fingertips.

He spoke in as level a tone as he could muster, seething inwardly.

"Your concern is unnecessary. I am never 'going there' again."

Lestrade sat forward, fighting an urge to cross his arms.

"Then show me."

No, hissed Sherlock's mind, still sparking with words, magical words that would make the man forget why he had ever come, send him crawling home on all fours. It rankled that this simpleminded Muggle—a friend, maybe, people said that like it should solve everything, but still a Muggle, still completely uninformed—thought he could walk in and try to understand something utterly beyond his reach. A bit of déjà vu that Sherlock didn't have time for right now. He didn't owe Lestrade anything. Certainly didn't owe it to him to give in to his ludicrous demands. But if he didn't…

John would remember. John would wonder. John had already heard everything that Lestrade, curse him, had let slip. As though he had a right.

And John would want to check for himself, and Sherlock could not…would not…watch his face again when he saw it.

So while his brain screamed, Get out! Sherlock leaned forward and unbuttoned his right cuff, rolling down his sleeve for Lestrade to see. The only track marks there were scattered and ancient, scarcely visible. Ten years healed.

"Happy?" he asked drily, because it didn't take a genius to deduce what came next.

Lestrade's eyes narrowed.

"The other one," he said.

Knowing it was coming didn't make it better. The only thing that would make it better was if John wasn't beside him, John with his thick fur and glinting green eyes and enormous, muscled frame, recognizable in spite of all this to one person in the world. The one person who had let him down most.

Sherlock tore open his left cuff, angling his arm away from John, who stiffened beside him. The jagged pink line of a badly healed scar was the freshest wound there, the cluster of track marks at his elbow long healed. Irrelevant. Faded. Memories. Unlike the bold, ugly black strokes twining down his forearm.

"Happy now?" Sherlock snarled, heart pounding, wishing the rush of blood in his ears could drown out the growl rumbling deep in John's chest.

Lestrade nodded, but couldn't tear his eyes from the tattoo. He'd seen it before, on a few memorable occasions, but it had always seemed somehow wrong. Even more so than the tiny scars left by the needle's prick. It was a strange tattoo. Deeper black than ink should be, it looked almost like something burned, branded into the pale skin. Something wrong and sinister and entirely not Sherlock.

On the job, there was one rule Lestrade never broke. A lot of the guys would have sneered at him for it—the ones who brushed off anything they didn't understand. But like his dad, like his old mentor, like all the best Detective Inspectors he'd known, Lestrade always trusted his instincts. And right now his instincts were telling him that figuring out this mark would go a long way toward unraveling the mystery that was Sherlock Holmes.

Because maybe he wasn't on drugs, and that was great. Better than Greg had dared hope. But anyone could see Sherlock was hurting. Even Sergeant Donovan, of all people, had commented. Sherlock Holmes and Doctor Watson had been…well, they'd been something. Something that was a whole lot more than most people ever experienced. And now that the doctor was gone, it didn't matter that Holmes was as brilliant as ever, that he strode around crime scenes in his long coat, plucking clues from thin air and unraveling mysteries in five minutes that would have taken the police force months. That something was missing, and Sherlock wasn't enough anymore. For himself.

Lestrade had no idea how to put him back together again. But in his experience, standing around dithering on the sidelines had never done anyone much good.

"Sherlock," he started, searching the other man's face. "What is that mark? What's so bad about it that John…"

He could never have said which was on his feet first: Sherlock, or the enormous wolfhound he called 'Toby'. Sherlock had yanked his arm back and was buttoning his sleeve with lightning fingers, avoiding Lestrade's gaze.

"Get out," he hissed, but his voice was drowned out by an even deeper, threatening rumble. It was the gut-wrenching roar of a low-flying fighter edged with the vicious snarl of cats in an alley, and it ran up and down Lestrade's spine and sparked some primal well of panic deep in his brain.

Toby the wolfhound was nearly as long as the sofa, stood at the height of Lestrade's chest, and was fixing him with fury—or hunger—in his wild green eyes.

Detective Inspector Lestrade had one rule. He always obeyed his instincts.

After the door slammed shut, Sherlock flopped back onto the sofa as though his strings had been cut. "Do me a favor, John," he mumbled distractedly, scratching at his left arm as the growling droned to a halt. "If you ever go on a murderous, maiming rampage, start with this."

A/N: Canon references, anyone?

And way to jump to conclusions, Greg. At least Dumbledore had the courtesy to give John his pep talk when Sherlock WASN'T IN THE ROOM!