"Why are we doing this?"

"Following a lead," Sherlock answered, switching on the light.

"It's a bit damp," said Mrs. Fischer helpfully.

"Yeah, thanks," Sherlock replied, shutting the door in her face.

"Shouldn't we be following up with the school?" I asked.

"Later." He had reached the center of the room. It was a wine cellar, all stone, with one book-case that fell just short of the gap from the ceiling to the floor. Sherlock was examining it punctiliously, running his fingers down the sides, searching for telltale cracks. He let out a soft cry of triumph.

"Help," he ordered. I hurried forward, and our combined weight was enough to slide it away from a worn wooden door.

"It's a not a secret passage," he said contemptuously, cutting me off.

"I wasn't going to say that."

"You were thinking it. It's just been forgotten. It's old wood, they would have replaced the door. But look at this," he added, indicating the doorknob.

"Also worn?"

"Yeah. Smooth. Someone uses this room regularly." Saying so, he flung open the door to reveal darkness. The air smelled richly poisonous, almost sweet, and I felt my temples throb as if in warning. It was dark, a dense, choking dark, and it was with no small amount of instinctual apprehension that I pulled Sherlock back from the threshold.

"It's dark," I said lamely, by way of explanation. "It looks like there's a staircase, and it's steep. You'll break your neck."

"I'll be careful."

We looked back at the entrance, frozen, and I thought I saw my own sense of foreboding mirrored in his eyes before it was extinguished by indefatigable self-control.

"Dark," he repeated. "Got your phone?"

I handed it to him.

"There's an app for that," he said with a half-smile, and suddenly our way was illuminated by the bright white light of the flash on the camera. "Comng?"

"After you."

When I reached the bottom of the stairs I realized that we no longer needed the phone; a flickering LED lantern hung from the ceiling.

"Someone's been here already," I murmured.

Sherlock cautiously stretched out a hand and touched a wall. "Recently, look."

His fingers came away wet. I checked the other walls.

"They're all wet," I said incredulously. Sherlock strode purposefully to the corner of the room and picked up a garden hose from the cold stone floor.

"Could be cleaning up…I don't know, mud?" I proposed.

"On the walls? Try again."

"Um…"

"There's a table back here, and-oh! Hello, what's this?"

I helped him pull the table into the light. There was nothing but a glass of water on it. He picked it up and sniffed it, then slowly started to tip it towards his mouth.

"No," I said firmly, taking it from him and placing it on the table. "At least not until we know what's in it."

He tipped some of it out onto the floor, and then frowned, evidently struck by paradox. "Where did it go?" he wondered aloud.

"Sorry?"

"The water, it would have splashed but the walls are still wet so it hasn't had time to dry, and in any case the light's too weak for it to have evaporated. Where did it drain to?"

"I don't see anything."

A low growl rose from the corner of the room that made us both jump. A German Shepherd stepped out into the light, bristling with anger at the intrusion of her sleeping quarters. Her lips were drawn back in a snarl, exposing healthy white teeth. Sharp white teeth.

I crouched to the floor, making myself smaller, and held out a hand, palm down. After a tense moment, the dog took a few steps forward and sniffed it curiously. I stroked her head, marveling at the thickness of her fur. She had been well cared for.

Sherlock smiled triumphantly.

"What?" I asked.

He waved a hand, as if to say it was inconsequential. "Nothing. I'll explain later."

Going back up the stairs, I braced myself against the wall, carefully, because it was still….

Dry.

"Sherlock," I said sharply.

He sprinted back and ran his hand against all of the walls. Dry. Dry. Dry.

I checked where he had spilt the water. Gone.

"I think we're being played with," he said loudly, directing the statement not at me but the whole room. "Well? If you're really a monster then come on out! They said you liked the dark!"

He hooked the chair with his foot and slid it under the lantern with an air of reckless bravado. Leaping up, he removed the lantern from its hook and held it out to the shadowy corners of the room, swinging it like he was warding off a demon.

"So," he said softly. "Time to stop hiding."

He switched off the light and we were plunged into total darkness.

I stood perfectly still, trying not to breathe too hard. I was sure he'd gone mad but not at all certain what to do about it.

And then something inside my head exploded. I couldn't even cry out, it hurt too much, like someone was driving a nail through my skull. I sank to the floor, shaking both with the effort of not screaming and the sudden, bone chilling cold. Multicolored bubbles burst in front of my eyes and I for a few moments I may have blacked out.

The lights were back on. Sherlock was at my side, dragging me upwards.

I noticed two things.

One, the walls were slick with water.

And two, the Slenderman itself was standing in the corner of the room, arms outstretched, its blank white face somehow more terrifying that any other apparition could ever hope to be.

I couldn't look long, though, since Sherlock had forcibly shoved me up the stairs but by that time there was no need, I was already running as fast as I could, anything to get away from that room, that sickly sweet smell, and above all that Lovecraftian horror lurking in there, hungry, waiting.

I slammed the door shut, only just now noticing that the dog had raced up the stairs with us. It skittered away, barking like mad.

"You saw it too?" said Sherlock, watching her tail disappear through the basement door.

"Yes."

"Then it's happening again."

"What is?"

"Worse than the last time. I'm hearing voices." He turned to me. "What does that mean?"

"I don't know," I said, massaging my head. The pain had gone as quickly as it had come, but my ears were still ringing.

"Headaches again?"

"And cold," I said. "It happened the first night too, in her bedroom. I thought I might have seen it then, too."

"Okay," he said, after a long, pensive pause. "Okay. So you saw it twice. And both times it was accompanied by the headache and the cold, right? This was my first time, but the voices started…oh, two days ago. I told Hopkins to keep me posted about anything unusual and he said that Donovan developed a violent nosebleed around the same time. Gregson's out sick, won't say why."

"But why them? Why us, come to think of it? And have they been seeing it too? What was with that water?"

"Oh, it wasn't water. That much is…" He trailed off, staring into space. "Obvious," he finished slowly. He smiled, then laughed. He looked a bit…off.

"Sherlock?"

"The wheels are in motion, John. Everything's falling into place. They're set to move, so…yes. Yes. Perfect." His smile broadened.

"Devil or no, we're going to catch ourselves a monster."

Gregson looked down at the file. It was the third time he'd gone through it in four hours, and he was getting nowhere.

Nothing about this case made sense, and the further he dug the less sense it made. That damned detective hadn't phoned in days. The Fischer case was cold, he concluded wearily. If Sherlock Holmes couldn't do it, nobody could.

Maybe he was pushing himself too hard. It was, after all, his first day back from a bout of flu. At least, that's what he had been telling everyone.

Two days previously he had awoken in the middle of the night to find a strange figure at the side of his bed. He first thought it might have been Ann, but switching on the light revealed not his wife but a glimpse of a shadowy thing with no eyes and too many arms. He screamed, woke Ann and probably the neighborhood as well, and two hours later he was shivering with fever.

He might have dismissed this as a delirious product of his own imagination, having spent far too much time on the Fischer case lately, but it happened again the next night. Not just the Slenderman-he would almost have preferred that-but Joey, his grandson, dead on the floor and wrapped, oddly enough, in plastic. The thing was cradling the child, rocking it to and fro in its many, writhing arms. The vision had flickered a few times before disappearing. His fever broke and that was the end of it. Nothing more.

He was interrupted from his examination of the photos by a knock at the door.

"What do you want," he growled irritably, annoyed at having his concentration broken. DI Dimmock slid in. He'd never liked Dimmock. Green as they came, with the possible exception of Stan. While Stan was in a class of his own when it came to naïveté, at least there was something honest about it. Dimmock had a kind of slimy ambition that made his skin crawl.

"Afternoon, Toby," said Dimmock casually.

"I'm very busy."

"It'll only take a minute." He closed the door. Gregson looked up expectantly.

"I'm getting a promotion," said Dimmock, with the barely controlled boisterousness of someone who felt it was about bloody time.

"Congratulations."

"You sound surprised."

"It's a bit sudden."

"I was something like eighty five percent above average this month. They came to their senses. Can't argue with numbers, eh?"

"No, you can't," he sighed, closing the file.

"Lestrade's packing."

"Good fucking riddance."

Dimmock chuckled. "Thought you'd say that." His humor faded. "It doesn't seem right, though, does it?"

Gregson shrugged. "He backed the wrong horse. Mind, this is the last time Sherlock Holmes is ever working with me."

"Lestrade's been here longer than everyone but you. Doesn't that count for something?"

He shifted uncomfortably in his chair. "Maybe, but I'm not going to argue with them. Why are you coming to me with this? Go to Sally. Or Anderson."

"Or, to be honest, anyone else," added Dimmock. "No one wants to see him go."

"Not my problem."

Dimmock was silent for a moment. "Okay. That's all. See you."

"Bye."

Alone in his office, Gregson came to the sudden realization that he was going to miss him. He was going to miss the repartee, the competition, even the occasional sabotage of his morning coffee. And something Dimmock had said brought back a memory from five years ago.

You can't argue with numbers.

Five years ago they had both been caught in a gang shootout in West End. Gregson was pinned to a dead end, with both his walkie-talkie and his baton lying fifty feet away. It was some spiky haired kid (what were they calling them now? Chav, it might have been) at the other end of the gun. He had been watching this one. He had either fired five bullets or six from his revolver, and neither of them were quite sure which. Gregson's life depended on the answer.

"Well," breathed the kid, and Gregson wondered if he had ever killed before. It was one of those moments that stretched out into forever and he realized that life did not in fact flash before your eyes, because you are too busy living as fast as you can when you've no time left.

Gregson, present, at his desk, slowed down the tape. It was automatic, unconscious-it seemed he could only recollect the event in slow motion.

The kid's finger pushes down on the trigger.

A shadow falls across his face.

I tried, Ann.

His ears are ringing.

There is a hole in the wall next to one of them.

And Gregory Lestrade is pinning the kid to the ground by his neck, and he looks up.

They hold eye contact for nearly ten seconds before he is gone again, into the firefight. Gregson, present, at his desk, opened his laptop and typed out a subject line on an email.

DI Lestrade

He hovered indecisively over the keyboard before beginning.

I've always believed in second chances.