It seems to take ages for the sun to set, even after trekking back to the castle, taking a long soak followed by allowing John to tend to the friction burns he's accrued in novel places, and sitting through an agonisingly leisurely supper. Sherlock spends the meal downing cup after cup of strong coffee and Victor and John follow his example, though with the addition of actual food. Even after the sun goes down it won't be completely dark until almost eleven pm this near to the solstice, but Sherlock wants them in place before then.

He sets each of them a side of the castle to keep watch.

"What about the front?" Victor asks, as he passes around torches and crowbars.

"Stones are different on the facing," Sherlock says dismissively. "Are you sure Justin has enough attention span to keep his watch?" They had asked him to stay up in the great hall to make sure no one came in that way. Sherlock had discounted it being an inside job almost completely after their search of the building, but one could never be too careful.

It would certainly make more sense but he was almost positive there was no existing way under the foundation from the inside, looking more would be a waste of time, they'd looked for an outdoor entrance too, but fruitlessly, this might be their only chance and he knows the thieves will strike tonight, knows it in his gut, he can feel the victory so close…

Victor nods. "He's a good lad. He's proud of the responsibility, he won't let us down."

"You think everyone's good," Sherlock grumbles, but lets it go.

"Right, so what are these for?" John asks, examining his crowbar. "Can't say I'm a fan of heavy iron bars these days." He rubs his lower back, still bruised, ruefully.

"If one of the stones drops down, we jam this into the sliding compartment underneath to stop it from closing completely after it. Then we might have a chance of finally getting into the chamber below. Obviously."

John rolls his eyes. "Obviously. So now what? We just hide in the tall grass until we hear something?"

"No, the walls are too long, it might be over without anyone hearing a sound if we stay in one place. We'll have to each patrol our section. Keep your torch off until you really must use it – we don't want to attract external attention if there's an associate keeping an above-ground watch and if any light makes it through the cracks while the thief is at work he'll likely abort before we can work out a way in."

"How will we see anything?" Victor asks. "After twilight you have no idea how dark it can be all the way out here, particularly on a cloudy night like this."

"I do," John says quietly. "You'd be surprised what your eyes can adjust to."

He imagines John in a dark desert somewhere, even more distant from city lights than here, had he patrolled alone in the pitch black night, had there been nights of a billion stars to walk under, or other nights even darker than these, waiting for an enemy to leap out of the black, he didn't like to ask but sometimes when John thrashed in his sleep Sherlock knew he was back there and longed to be there with him, to learn what it was like to be that brave, but right now John's still glowing in the dark, like the northern lights, he doesn't want him to go out of sight but there's more important things now…

"Enough talk," Sherlock cuts in. "Let's get to our stations. Remember, try to jam up the mechanism before calling out or they'll know something is up."

The others disperse. Sherlock's given himself the eastern side of the castle, facing the ocean, so that he won't be far from the action if something happens either on John's or Victor's side. He starts walking the length of the wall, pacing with slow, measured steps, peering carefully at each foundation block as he passes for any hint of a change.

It's fully dark now, a darkness Sherlock is not accustomed to, even though his eyes seem to be coping as John had said. It's never this dark in London, at least not outside. It's not possible. He knows his friends are only a few hundred metres away, but it feels like he might be the very last person in the world. It feels like the world itself might very well not extend beyond the tiny radius which he can make out dimly around him.

If there was a hell, is this what it would be like, a world of total blackness with only himself and his brain, eating itself alive while things moved in the unrelenting shadow beyond, never to be known or studied, no new data, no new problems, no John, just alone and trapped and forever bored, so bored it should kill him if he weren't already dead…

A cold fog has moved in, making the experience even more unearthly. He pulls his coat more tightly around him and turns up his collar against the unpleasant moisture trying to seep into his body. He refuses to let his mind wander and falls into an almost trance-like state as he walks up and down his route.

After two hours he finds he's beginning to tire, both mentally and physically, but reminds himself it's infinitely preferable to laying motionless on the ground in this weather. And more difficult to accidentally fall asleep. He's tempted to check on how the others are faring, particularly Victor. John's used to this, but Victor's determination might be starting to wane – he's not accustomed to extended discomfort and Sherlock doubts his fortitude. Still, it's his home so he ought to be motivated, and calling out or leaving his post to check on him aren't really options. Sherlock has to content himself with not knowing.

Two more hours pass with equal unpleasantness, although Sherlock supposes the numbness in his extremities is preferable to the original painful cold he had felt. It will be starting to get light again in an hour and a half, and he's beginning to doubt his estimation of the thieves' persistence. Maybe they had called it off once they knew he and John were investigating.

It didn't matter if they'd given up, he'd still find them, he'd still solve it, he wasn't going to leave this one no matter how ridiculous and hopeless it got, even if he had to spend the next ten years in god-forsaken Northumberland digging out the foundations with a spoon to get the answer…

He's shaken from his reverie by a shout off to his right – Victor. Instantly alert, he springs in to a run, using the castle wall as a guide to keep from stumbling. John overtakes him in the dark, a bright streak like waving a sparkler in a slow-shutter photograph, navigating almost blindly at a speed that even Sherlock wouldn't dare under these conditions.

Victor is kneeling on the ground at the base of the wall, near to the front of the castle. There is a gaping hole before him, exactly like the others.

Sherlock swears. "You missed him! That may have been our only chance. Wasted! Why can't you ever focus?!"

"Sherlock, stop it," John tells him irritably. "Victor, what happened?"

"I was on the other end of the north side, and I thought I heard something, so I turned around and walked back quickly, just in time to see the lower stone sliding back into place. I wedged the crowbar in there but…" He holds up his tool and Sherlock can just make out that it's been sheared in half. "That's when I shouted."

"That's more than just man power that did that," John points out. "They must have some machinery on their side."

"Quickly, did you hear anything mechanical? An engine, a whirring noise, anything?" Sherlock demands.

"No, just stone against stone. I'm lucky I heard anything at all, the distance I was at. I just can't believe the whole process took…what? Less than three minutes from the time I left this spot till I returned."

"Ack, they are right beneath us! We're missing them, right now, as we speak!" Sherlock shouts, frustration and anger boiling over, pacing in a tight circle before the missing block.

"I know you're under there," he yells at the ground. "I can feel you there and this is not the end of it! Fuck!"

So close, so close, failure now is not an option, he should have taken this side, he never would have missed it, he'd have thrown himself down the rabbit hole if that was what it took, let the stones slice him in half, now all he's got is impotent, useless rage, at the thieves, at the building, at the very stones themselves, at the Norman masons, at himself, at Victor and John and anyone who dared to get within his eye line…

"Sherlock…" John begins, approaching him carefully, as if he were a feral dog. He knows he's not acting his sanest right now but he hates it when John gives him that look. He hates being handled, even by John, even when he knows he's being at least vaguely unreasonable.

"Shut up, just shut up," he barks. "The thieves are literally underneath our feet right now and we can't do a single thing about it. Probably laughing at my humiliation." He lets out another impressive stream of curses aimed at the ground and continues his pacing.

"I am going inside." John says calmly. "I am going to have a cup of tea, a hot shower, and a sleep – and hope that I one day am reunited with the feeling in my toes. If you would like to join me for any of those things, feel free. Otherwise, enjoy stomping in the dark and swearing at the turf in a freezing fog for as long as you like."

He spins on his heel and walks towards the front of the castle. After a slight hesitation, Victor follows, leaving Sherlock alone.

Good riddance, they were being useless tonight, he shouldn't be surprised about Victor, but John, even John, he should have managed something, Sherlock doesn't know what, but John's the man of action, he ought to have done…

It's entirely maddening, knowing how close they are, knowing the answer is literally right in front him and being able to do nothing about it. It's like being deliberately taunted. He is sorely tempted to obtain a backhoe and dig them out like a nest of voles, damage and injury be damned. He needs to know how, he needs to know why, the frustration of the situation overwhelming even his admiration for such an elegant and brilliant scheme.

Slowly, though, his rage recedes, if only due to sheer exhaustion and chill. It is a tad unseemly to be standing outside in the middle of the night screaming at people who may or may not be able to hear him or even still be there. He collects himself with difficulty. It is very cold and he can't deny he's reaching the end of how long he can go without sleep and still be effective.

Grudgingly he goes inside and makes his way up to their rooms. He can hear the shower running in the bathroom and the thought of warm water – and warm John – is suddenly very appealing. He strips out of his damp clothes and creeps into the bathroom nearly silently. John jumps with surprise as he slips into the steam-filled shower, but doesn't order him out. The water is painfully hot on his frozen limbs, but he doesn't mind.

John likes scalding showers, ones that make your skin feel like it wants to peel off and turn your bones to jelly, he says he's just grateful for the hot water, that it's the only way he feels clean sometimes, it's too hot for Sherlock's delicate skin, always makes John turn the heat down, but tonight he doesn't care, likes how much it hurts because it means he hasn't frozen to death…

John lets Sherlock come up behind him and put his arms around his slippery waist. He's bright red from the heat, parboiled, and feels almost like a person-sized hot water bottle in Sherlock's grasp.

"Are you done now?" John asks. "You sure there's nothing else you'd like to say to the empty countryside? A few more choice words for the local inhabitants? I'm sure they could hear you clear into town."

Sherlock tries not to bristle at his taunting, unfair though it seems. "I'm done," he agrees reluctantly, resting his chin on the top of John's head.

John sigh, patiently. "It shouldn't be this difficult to stay angry with you. So… what do we try next?"

Sherlock says nothing.

"You don't know, do you?" John says, turning to face him, catching the look of uncertainty on his face before he can quite hide it away. "Well, never mind that. You'll figure it out after you've had some rest."

John's face is comfortingly confident, wreathed in hot steam, and Sherlock relaxes despite himself. Once they are both clean, John has to bully him into going to bed and even then he lays there rigidly, thinking the case over and over, determined not to succumb to sleep before he has a plan to solve it. He's aware of his thoughts growing less coherent and productive with each go-round, but stubbornly refuses to let it go until at last sleep takes him against his will.

Consciousness and the answer hit him at almost exactly the same moment and he wakes with a shout, startling John beside him. It's not entirely safe to wake John without warning, and he crackles brightly as his brain assesses the danger level, cycling through possibilities and reactions until he subsides into a low, annoyed shade upon determining that it's just Sherlock having a brainwave.

He didn't do it on purpose, but it's a nice bonus, seeing him flick from soldier to doctor to bedmate in a few heartbeats, knowing that had his shout had been one of alarm John would already be armed and on the attack before his conscious mind even woke up…

"Christ, I'll never get used to that," John mutters, rubbing sleep from his eyes. "Bloody menace!"

Sherlock grins at him. "I know what's next. Get up. We need to find Victor. No, don't bother getting dressed, hurry up!"

John grabs his dressing gown and follows Sherlock, still grumbling, but Sherlock can see how sharply he's gleaming, caught up in Sherlock's excitement. He bursts into Victor's rooms, John trailing apologetically after, and gives the still-sleeping man a hard shake.

"Victor! Up!" he shouts in his ear and slowly Victor claws his way towards consciousness.

"Sherlock, wha…? John?" he manages. "Is everything…alright?" He yawns deeply and shakes his head, blinking. "What time is it?"

"Nearly noon, you lazy bastard!" Sherlock informs him cheerfully. "We've got work to do!"

"Work? What?"

He'd never known a man to sleep so soundly as Victor, he used to amuse himself by determining the exact disturbance level, down to the decibel and amount of physical force, that Victor could tolerate before he finally woke, playing every type of music he could think of and piling objects on top of him, from the cat to a dozen glasses of water to a tower of blocks, while he slept, not that he'd known how many other men slept, mainly John and Mycroft, who didn't sleep any longer or more deeply than Sherlock did….

Sherlock smirks. "We're going to find the entrance to tunnel running underneath the foundation. And when we find that, we'll find our man. Or men." He preens visibly, but John and Victor do not look as awed as he'd hoped.

"Didn't we try that?" Victor asks.

"Yes, but we were looking inside the castle and on the immediate grounds. There has to be a way people are getting under the blocks to steal them, and if the entrance isn't nearby, then it must be far off and we have to find it!"

"And how will we do that?"

"By looking!" Sherlock says, exasperated. They really ought to be more impressed, even if it is an obvious next step and he is a little ashamed he hadn't thought of it earlier. "We do a systematic sweep of the land in a wide radius around Corvin Castle, until we find the entrance."

He's determined, he'll wear out his boots, all their boots, all their legs before he gives up, there's got to be an entrance and he's going to find it if it kills them all…

"That's… a lot of land…" John says weakly.

"Which is why we need to get started right away!" Sherlock claps his hands. "Come on, get dressed, both of you, I want us outside and ready to go in twenty minutes!"

Once everyone is more or less ready, Sherlock divides the land around the castle up into even thirds, like overly large pie pieces. "Now, we start here and sweep back and forth like a searchlight, moving outward until one of us finds something, then he calls the others. Obviously the entrance has been well used lately, so there should be footprints, trampled plants, a path near it even it is well disguised. It might be a hatch or hidden by a cave or cairn. But I'm betting once we see it, it will be obvious."

"How will we call if one of us finds it?" John asks "No mobile service, remember?"

Sherlock pulls out his Browning and fires three shots in the air as answer.

"Fantastic," Victor mutters, and goes back inside to retrieve one of his hunting rifles before they set out, each in a different direction.

Victor could never hunt anything in his life, but he always did keep up appearances, he was a good shot, they once had gone stalking with his father and he had successfully put a bullet exactly three inches to the right of a stag's ear six times in a row…

Sherlock thinks he will have had quite enough of walking when this case is over. It's coming horrifyingly close to exercise. And sweeping back and forth like this is more tedious than enjoyable, particularly as the fog and clouds have persisted and it is now a surprisingly chilly afternoon for nearly July.

His progress is slow and unfruitful, and by the time the sun starts to dip to the horizon he's forced to admit he's not going to find anything else today. And he's far enough out now that it's unlikely any tunnel would be quite so long. Perhaps the other's have found something, but he's heard no shots.

Sherlock tramps back in defeat and meets Victor in the dining room, where he is warming himself by the fire with a stiff drink.

"Good Lord, did you just get back?" he exclaims, jumping up pressing his drink into Sherlock's hand. "Here, you need this more than me. I'll call for some food for you, I ate already."

Victor gets Margaret to put on something hot for Sherlock and settles back into his chair. "So, no luck either? Neither you nor John? I must have walked 20 kilometres today myself and I've been back two hours already."

"You haven't spoken to John?" Sherlock, previously slumping over his drink, snaps to attention.

How had he forgotten about John, why hadn't he checked for him right away, was he that tired and caught up in the case, of course he was, he always was, John knew that, would have been waiting for him not expecting Sherlock to seek him out, something was wrong…

"No… I mean, I thought you'd both gotten back earlieralready and were upstairs. He wasn't with you then?"

"No," snaps Sherlock, springing out of his chair and running up to their room. He finds it empty and dashes immediately back down and out the rear door, shouting John's name into the darkness.

"He's not back?" Victor asks from behind him, knowing the answer.

"I have to go after him, now!" Sherlock declares, sprinting back inside. Victor finds him up in their rooms once again, frantically collecting torch and John's medical bag and damn it, what else?

What else would he need, something warm and dry to wear, something to eat, rope, a weapon, did he have all those things, did he even need them, if John were here he'd know…

"Sherlock, you can't!" Victor tells him. "It's pitch black out there, he could be almost anywhere. It's like looking for a needle in a haystack. Blindly. We have to wait until we can see something."

"No, now," Sherlock repeats, shoving a clean jumper and thick socks into John's bag.

It's dark, he should have known, should have been able to tell John's light was missing, he could always tell, now he feels like he's being squeezed in a vice, cold inside, no light, no direction, adrift, he hadn't known how much he'd come to rely on John's bright and warm presence until it was gone, he closes his eyes looking for the little spark in his head that is John and stays lit even when he doesn't know where John is, and that's gone too, it's never been gone before…

"We'll never find him. Look, it's not that long until dawn. I promise as soon at it's light I'll have dozens of people down here scouring every inch of my land for him. It'll be all right, he's tough. You'll only get yourself hurt or lost like this." His voice is soothing, reassuring, but it only enrages Sherlock.

"No!" he yells, slamming his palm on the dresser. He's breathing fast and shallow, his heart pounding, terror filling his mind and blockading rational thought. "I won't wait one minute more. He could be hurt or dying or captured or—"

Dead, he might be dead, fallen of a cliff, drowned in the sea, head smashed open on a rock, stabbed by a criminal, shot accidentally by a hunter, no longer John but just so much meat lying somewhere, growing cold, rotting, being fed on by foxes or ravens, never to move again or touch Sherlock or make things stop being Not Good for him, how could Sherlock possibly live in a world where that could happen, he couldn't, he'd have to leave, have to….

Suddenly he feels strong hands on his shoulders. Victor has gripped them tightly, forcing Sherlock to be still.

"Sherlock." His blue eyes are wide with compassion.

Sherlock meets Victor's gaze. "It's all going grey," he tells him, before he even knows what he's saying. "Black and white and grey and getting darker every second."

Victor is taken aback, but when he speaks his voice is firm and calm. "We will find him. I promise. We'll go right away, night be damned. Okay? We'll get him back for you. But you have to stop panicking. You're no good to him like this."

Sherlock snaps out of it. He nods and forces his breathing and heart rate to slow, even though to wait for another moment is agony.

"Good," says Victor. He leans forward and touches his forehead to Sherlock's briefly. He whispers. "We'll find him, I swear to you."

Victor seems like he understands, he makes Sherlock come back to sanity, but how could he understand, he's never had someone who was a physical requirement for existence, someone without whom the world became unbearable and unfaceable in every way, if he had he'd be with them now or dead, but Sherlock is grateful for his loyalty and comfort in the moment, even if he can't ever really know what it's like, like being pulled apart, like being drowned, like falling into that dark alone place he was before but this time with no one to come and pluck him out of it…

Sherlock hurriedly pulls on his coat and picks up the bag and the torch, ready to run out again but Victor stops him. "Wait, we can't just run out like this. We need a plan. And something better than stumbling around in the dark on foot."

Sherlock halts his progress reluctantly. "Do you have any vehicle that could navigate the terrain?"

Victor shakes his head. "Not here. Look, I am going to ring the police and everyone else who might be able to help, but I know you don't want to wait for that. You should get going as soon as possible."

"If not on foot, then how?" Sherlock demands, impatient, mind starting to go to bad places again.

"Well… how much of your riding lessons do you remember?"