"You've really stuck your boot in it this time."

Sherlock scowled. It hurt. "Yes. Thank you, John. There is no situation that is not made better by stating the obvious." He lifted his head and that sent the room spinning. When it finally slowed, and the floor and ceiling returned to their proper places and his faltering gaze settled, he found his friend had taken no offence with the churlishness of the reply. Instead, he was being regarded with a mixture of fondness and concern.

Something seemed off about the situation, but Sherlock couldn't place his finger on what was wrong. His head was pounding, and equilibrium had not returned in full measure. His stomach lurched and he wretched, coughing up air and bile.

John wiped his mouth. Sherlock leaned into his touch. He had missed it, as he had missed John's companionship these many months. A data point slotted into place and Sherlock sighed. "You're not really here." He dropped his head and blinked rapidly several times in succession. When he opened his eyes again John was still regarding him with the same fond expression.

"Yeah, we'll get to that in a minute." John knelt at his side. He thumbed Sherlock's left eyelid back and peered close. "Who's the Prime Minister? Wait a minute. You always have trouble with that one. I'll make it easy. Who's the Queen?"

"Elizabeth."

"Good. Now follow my finger."

Despite the fact he knew he was following the instructions of a hallucination, Sherlock complied, watching John's index finger as it travelled from side to side and then up and down as if he was delivering a benediction.

"Right," John said as he fingered Sherlock's torn shirt sleeve and examined the arm underneath. "You're a bit concussed and hypoglycaemic from skipping too many meals, but your biggest problem at the moment, aside from being held prisoner, is you're high as a kite. You should see the state of your pupils and the bruise on your arm."

"Not intentionally," Sherlock snapped back. The idea John would think him capable of partaking whilst on a case was offensive.

"Did I say anything?" His imaginary companion looked around the office space as if noticing it for the first time. It was located at the front of a warehouse where drugs smugglers repackaged their wares for further distribution and contained the usual tired furnishings one might expect to find; a desk, file cases, and a water cooler.

As his head cleared, small details made themselves known. After infiltrating the operation and collecting a suitable amount of information, Sherlock had taken his evidence to the local narcotics squad. It turned out that had been a mistake. When he'd arrived for his shift the next afternoon there had been a reception committee of heavy hitters organised by the same, highly decorated, Kriminalkommissar with whom he'd confided. "I need to get out of here." He tipped his head over his shoulder indicating his bound hands. "Help me."

"Can't." John tried to work the ropes around Sherlock's ankles. His hands passed right through them. "Hallucination, remember? The best I can do is cheer you on. Now come on, you taught me that one time we were both drunk off our asses. You can do it now."

John was right. He could do this. Sherlock rolled onto his side and hugged himself into a ball. With his shoulders as relaxed as he could make them, he took a deep, calming breath and brought his bound arms underneath his legs and feet. He was sweating and nauseous from the exertion as he brought his knotted wrists level with his mouth, but John was positively beaming. Whoever had bound him had done a substandard job of it. Normally one to excoriate sloppy workmanship, even among the criminal fraternity, Sherlock blessed him as the cords loosened and he slipped his hands free.

John frowned and held his finger to his lips. "Keep it down, I think there's someone outside."

Sherlock froze over his ankle restraints and listened hard. He heard nothing more than the sounds of others engaged in their labours. But John was right, caution was the order of the day. He waited a few more beats to make sure that no one was coming, and then quickly undid the last knot.

"Slowly," John cautioned. "First your knees and then your feet." He sighed, a sound of concentrated frustration. "I'd help you if I could."

"I know." Sherlock concentrated on the task at hand, ignoring the gentle rebuke for going at his crusade alone. Despite his intentions he wondered if John, the real John, would be so understanding when he finally returned home.

"That's good." The note of pride was back in John's voice as Sherlock regained his feet. "Use the wall. Give yourself a couple of seconds. The door's out. Can you make that window?"

Sherlock glanced upwards. The office was below street level and from approximately two meters above, freedom beckoned. There was no way he could move the heavy oak desk without alerting the guard who was no doubt without, but the chair behind the desk offered possibilities.

"Don't forget the ropes." John mimed wrapping his hands to protect them against the glass. Sherlock nodded, collecting the pieces and carrying them with him as he positioned the chair and clambered onto it. It rocked dangerously, the springs in its seat and back made for ergonomic comfort and not for use as an impromptu ladder. He shifted his body to compensate and flipped one of the pieces of rope over the utilitarian iron curtain rod. It held against his weight. John gave him a thumbs up as he started to climb.

It took what seemed an age. His head spun and his stomach continued to roil. His muscles protested the exertion after being bound but Sherlock ignored everything except for John's litany of encouragements. He was exhausted when he reached the window. His breath was ragged, and sweat dripped into his eyes as he rammed his elbow through the glass and then used his wrapped hands to clear away enough shards so that he could climb through without cutting himself. Outside, the night air was frigid and filled with the promise of snow. Even though it hurt to do so, Sherlock filled his lungs with the bracing air before clambering over the sill.

John was waiting for him, leaning against the bricks as Sherlock hauled himself onto the pavement. "Can't rest. Sorry. Come on. Just a few steps 'round the corner. Then you can catch your breath."

Sherlock nodded and crawled. Left hand, right knee. Right hand, left knee. Fourteen times he counted each repetition of the sequence and then he collapsed onto his belly in the stinking shadows with John's ghostly hand caressing his brow.

"John," Sherlock muttered. He had no idea how much time had passed, only that it had as he'd lapsed in and out of consciousness.

"Still here. Glad to see that you are too."

"Doesn't that go without saying – " Painfully, Sherlock abused his muscles further as he struggled to sit upright. He leaned against the alleyway wall and regarded his companion. "– if you are a product of my disarranged mind?"

John shrugged. "Yeah, I suppose it does. Sherlock – "

"Shut up. I'm listening." He closed his eyes and concentrated on the minute details of his surroundings. The smugglers operated out of an industrial estate, one of three shipping and distribution warehouses scattered between a half a dozen light industrial manufacturing concerns. By day they were a legitimate operation, sending lorries full of inexpensive novelty items across Europe. It was only during the night shift that they engaged in their more felonious enterprise.

A train rumbled by, the source of the noise coming from the opposite end of the alleyway. Sherlock smiled. Riding the rails was out of the question, even if he'd been early enough and had the strength to leap onto one of the open-sided cars that commonly composed the freight-liner, but there was a large, unguarded car park between the buildings and the tracks.

With John watching anxiously, Sherlock began the arduous process of regaining his feet. He splayed his already abused hands against the bricks and wondered if he wouldn't be better served by crawling the distance and thus saving his strength.

"You can do this," John said. Sherlock nodded and heaved himself to his feet.

Crossing the alleyway seemed an interminable journey, though logically, he knew it was no more than twenty feet. Still in its protective shadows, Sherlock leaned against the wall and regarded the cars parked beyond. There were several that looked as if the owners cared little for them. Granted, that wasn't the best predictive factor for deciding which door was unlocked, but the odds were better than trying the handles of the more carefully maintained vehicles. As he had no tool at his disposal for jimmying a lock, and no desire to risk further exposure to either the unwanted attention of an alarm or the chilly night air that would result from breaking a window, it seemed the safest course of action.

The first three doors were secured, but the fourth, belonging to an ancient Volkswagen, opened when he lifted the latch. A cursory search for the keys came up empty. Sherlock hadn't the energy to feel disappointment. He hot-wired the car as John glanced around furtively. "Stop doing that!" Sherlock hissed. "Someone will see you." The engine sputtered and turned over as he realised what he'd said. In the excitement, he'd forgotten that John wasn't really by his side. He sighed and pulled out of the car park.

"You need food and rest. A place where you can sober up."

Sherlock glanced at the passenger seat. John was still there. Hallucination or not, he had a point. "I know. I can make it to the next town. I've got cards and money in the heel compartment of my shoes." He patted absently at his breast pocket. "And my pay packet in cash, if you can believe it. I'll be all right."

They drove in silence as the desolate environment of the industrial estate gave way to clusters of modest houses and finally the outskirts of a small town. John cleared his throat, as if uncomfortable, and then spoke. "Sherlock, why are you doing this? You've been gone for months, kicking over hornets' nests, but what's it accomplishing?"

Sherlock frowned. It was important that John understand. He had the gist, but as usual he was sloppy about the details. "Not hornets' nests. You're mixing metaphors. Moriarty was a spider at the centre of a vast web. I've been breaking the strands."

"Fine," John conceded. "You've been breaking spider silk. Same question stands. Why? Moriarty is dead."

Sherlock sighed. He should have explained this before he left, but there had been no time. "His organisation lives on. There are others working for him. Key operatives. I've taken out a few of them, but the one I really want always seem to be just out of reach." He slammed the steering wheel, venting months of frustration at his failure to find Moriarty's primary lieutenant and then slumped back against the seat cushion, releasing a faint odour that had lingered in the elderly car and igniting a nearly visceral craving. He'd noticed the source in his search for the keys, but hadn't absorbed its significance until that moment. From the glove box he retrieved his prize, delighted to find three cigarettes and a lighter in the packet. Sherlock lit up, sighing with satisfaction as he filled his lungs with smoke.

"You've started again."

Sherlock glanced over. John seemed slightly less substantial, although no less disappointed by his lapse. "Nicotine helps me to focus. Without you to provide a sounding board, I needed it."

"That's my point!" John said emphatically. "Moriarty's operation is in shreds. But this mysterious lieutenant you've been searching for, if he even exists, you'll never find him roaming aimlessly. Come home. If he's out there we'll find him together!"

Sherlock inhaled more smoke and contemplated the idea. Home was a word that conjured up images of nights sat in front of a comfortable fire. Of John in his chair bent over his computer, distorting another one of their cases into a tale of high adventure. Mrs Hudson fussing, usually bearing a plate of cakes as she complained about the state of the flat. A life he had sacrificed to make sure those he cared for were safe.

A horn blared. Sherlock jerked on the wheel and pulled back onto his side of the roadway just in time to avoid an oncoming lorry. He saw a sign for a well known hotel chain and pulled into its car park. He knew he should abandon the vehicle somewhere else and walk back, but he was done in. He parked and locked the car, took one last hit off his cigarette, ground the butt out under his heel, and then did what he could to straighten his hair and clothing before presenting himself to the hotel clerk. "Stay with me," he said to John's spectre. "Just for a little while longer." In the short time of its existence Sherlock had come to rely on the hallucination, just as he had the man himself.

"I'm never far away, Sherlock. You know that."

Sherlock smiled, acknowledging the truth of the statement. It was easier to count the times John wasn't close to his thoughts.

Inside, the clerk barely looked at him as he took Sherlock's money, handed over a key card, and promised to send along a tray of sandwiches and coffee. He pointed the way to the lift and then went back to browsing the Internet on his mobile.

After the journey to his room, Sherlock felt as insubstantial as John now appeared. "I can see through you." Sherlock raised a hand and traced the shell of John's ear and the line of his jaw.

John leaned into the caress, his eyes closed and expression wistful. He rose up on his toes as Sherlock bent close and pressed their foreheads together. "You're coming down." He wrapped ghostly fingers around Sherlock's wrist. "Eat and sleep. You'll be all right."

There was a sharp knock at the door. The clerk, though indifferent, had been efficient. "I'm coming," Sherlock growled, unwilling for the moment to end. The knock repeated, even more sharply. When he opened his eyes, John smiled at him and then he faded away.

Sherlock tipped generously enough that the porter overlooked his surly greeting, ate the packaged sandwiches and instant coffee without tasting them, and then lit a second cigarette, mindful of the smoke alarm. The frigid air from the open window helped clear his head and by the time he scrubbed and rinsed away several days of accumulated grime and crawled into bed, he felt nearly himself again.

He lay in the darkness, contemplating the the idiosyncrasies of the disordered brain, and decided the experience had been a useful one. Because of John, or at least the version his brain had constructed of him, Sherlock had survived the night. He'd also reached a conclusion. He had struck at the heart of Moriarty's most profitable enterprises, crippling them. Smuggling operations like the one he'd infiltrated were meaningless distractions, better left to local authorities. John and the others were in no immediate danger, and he would be happier and more productive among familiar surroundings.

It was time to go home.