The sounds of Scotland Yard's offices were familiar to Sherlock—clacking keyboards, ringing phones, the chatter of various voices issuing orders or just catching up on last night's game, the pop-hiss of a coffee machine spluttering out the start of a new batch of tar… He had been here a thousand times, had processed every sound-wave. He knew the sounds of this building as well as he knew those of his own home.

There was a sound missing, though. A hole in the matted, felt-like surface of white noise as Sherlock walked down the long hall that led to the holding room where John waited. A sound that Sherlock had only, in the past few months, been able to add into the mix: that of John's footsteps echoing his own. Somewhat shorter and quicker, given John's lesser height, with a military precision and a touch of the medical soft-step, a blend of the institutional and the martial. And today, for the first time in a very long while, it was missing.

Sherlock tried to push his uneasiness aside as he followed Lestrade down the hall, focusing on the fact that John was alive, he was unharmed—or else they'd be at the hospital, of course—and he would soon be following Sherlock all over England again. The missing footsteps would return.

An image from childhood, long buried in Sherlock's mental maze, reared its shaggy head. Peter Pan would regain his shadow.

"He's right in there," Lestrade said, gesturing with one hand. "And Sherlock…" his voice trailed off.

"Yes, Lestrade?" Sherlock snapped. He reached for the door handle, only to be stopped by the detective inspector's firm hand on his wrist. He looked at Lestrade's grey face. Too little sleep recently. Should cut back on the coffee. Migraine coming on. Ex-wife is asking for money again.

"Be gentle."

Sherlock furrowed his brows, but Lestrade said no more, releasing him and stepping back.

The doorknob in his hand suddenly felt cold, as if there were a wall of ice on the other side. Sherlock twisted it, and pushed the door open.

"John?"

There he was. Sherlock swept into the room, his eyes scanning John's wrinkled, gaunt frame with the precision of an electronic device, cataloguing every scrape—three, one to the left temple, two on the right wrist—bruise—one, left eye—and sign of harsh treatment—wrinkled clothes, he's slept in them, if he's slept at all. Gaunt cheeks, little to no real nourishment, but no need of emergency fluids. Grey skin tone…Why is he not speaking?

"John. John, can you hear me?"

John Watson, his blonde hair at least three shades greyer than when last Sherlock saw him, said nothing. Didn't even move. He sat bolt upright in his seat before the table that sat in the center of the room, staring in front of him with a blank-eyed gaze that didn't even seem to register that Sherlock was in the room.

"John?" Sherlock bent over to meet John's gaze. It was as though he wasn't even there. He touched his flatmate's shoulder. "John. You're safe. Wake up—are you alright?"

No response.

Puzzled, and with the buzzing edge of fear tingling at the corners of his mind, Sherlock examined John more closely. His breathing was normal, as was his heart rate. Pupil dilation was acceptable, if a bit sluggish. No indication of drugs or alcohol…

"Lestrade." Sherlock pulled the door back open, his eyes never leaving his eerily-still friend. "Get in here."

DI Lestrade stepped inside the small room and pushed the door shut behind him with a sigh. "No change, then."

"You knew he was like this?"

"I'd hoped seeing you might…snap him out of it." The detective inspector shrugged his shoulders. "We don't know what's wrong. He was like that when we found him."

"Does he respond to anything?"

"He will be led; he makes no resistance to that. But he never talks, never smiles…he blinks. That's about it."

Sherlock knelt beside his friend, laying a hand on John's jumper-clad arm. "Something is wrong," he said, knowing that he merely stated the obvious but unable to think of anything else. "Post-traumatic stress? He has a history."

"It seems likely. But we don't know why, or how to…" Lestrade waved a helpless hand "…how to wake him up, for lack of a better word."

Sherlock stared into John's dead eyes, watching the army doctor blink mechanically.

"I'm taking him home."

"By all rights, he ought to go to a hospital," Lestrade protested. "I've already called over for them."

"Your medical personnel examined him?"

"Yes…"

"And?"

Lestrade shoved his hands into his pockets. "They say there's nothing physically wrong with him. But he should still—"

"I'm taking him home, Lestrade."

There was no arguing with that tone of voice. Sherlock took John's arm and helped him to stand. The shorter man obeyed without emotion, lifeless as a robot. Lestrade watched as Sherlock led him out into the hall and then toward the outer door, Sherlock holding John's elbow in one hand, with his other arm—clad in that great black coat as always—wrapped around the shorter man's shoulders in a gesture that was both practical and protective.

Two sets of footsteps tapped down the hall, but the sound was still not right.

No, it wasn't right at all.