Author's Note: I'm not sure yet if this will be a one-shot, or a series of reactions between Sherlock and John after the former's return. So, I'm not listing it as "Complete" just yet. If you have any opinions on whether it should continue or not, I would appreciate the feedback (plus any other comments, as always!).

Again, thanks to Ariane DeVere (Callie Sullivan) for her livejournal transcripts of Sherlock. Invaluable for fact-checking and referencing dialogue!

On with the show…

Figuring Out the Why

"Mrs. Hudson!" a low baritone voice rang out through the otherwise silent building. A few moments later there was a sound of footsteps, and the older woman appeared in the doorway of the upstairs flat.

"Sherlock?" she called. "Everything all right, dear?"

Sherlock glanced up from his microscope. "Yes. Just need my phone."

Mrs. Hudson's brow furrowed. "Your phone? I don't have that."

"No, it's in my coat pocket. Only just across the table." His attention back on the microscope, Sherlock pointed at the coat draped just out of his reach, then rotated his hand palm up. Waiting. "Please," he added.

"Young man," began Mrs. Hudson firmly, "I am not your housekeeper, and I'm not your servant! If you need something, then stand up and get it yourself!"

Nonplussed, Sherlock looked up again. The response was not exactly what he was looking for. "It's not an impossible request," he argued. "John would've fetched it for me."

Mrs. Hudson walked into the kitchen, shaking her head. "Well, add 'John Watson' to the list of thing I'm not, then!" Behind Sherlock, she began collecting dirty, disposed dishes and depositing them into the sink. "Honestly, dear, you've been back only a few days and the flat already looks a mess."

"That was all John's department. Not mine."

"Well, maybe you should work at bringing John back, then."

Sherlock snapped his head up and spun around. "You honestly don't think I've tried?!" he barked.

The older woman jumped and turned to meet his gaze, her eyes wide and frightful. Sherlock's face immediately softened when he saw her reaction. "I'm sorry, Mrs. Hudson. Really, I am. But I've told you: I've spoken with John and he's—"

"Not interested in hearing your apology. I know, dear." The dishes all in the sink, Mrs. Hudson reached down and stroked Sherlock's hair. Unconsciously he leaned into her touch: aside from his mother, she was the only person whose physical affection he would instinctively return.

"I don't understand why," Sherlock admitted, trying to keep his voice even. "Why can't we just…go back to how things were?"

Mrs. Hudson leaned down and gave him a quick kiss on the top of his head. "Not my place to say, dear. You need to figure this out on your own. And for that, you need to talk to John." With one more stroke of Sherlock's hair, Mrs. Hudson turned and left the flat.

Sherlock narrowed his eyes. John wouldn't talk to him, so that idea was out. And figure what out? He'd faked his death to save John, Mrs. Hudson, and Lestrade's lives. For two years, he'd worked destroying Moriarty's network, ensuring their safety. Then he had come back. Lestrade and Mrs. Hudson had been overjoyed to see him. But John? Well, Sherlock's nose was still sore from John's volatile reaction to what Sherlock had (wrongly) anticipated as a joyous reunion.

Sherlock drummed his fingers on the table, and in the silence of the flat, the slight noise took on a deafening echo. That was something new he'd noticed upon his return. During the day, Mycroft would come by, or Lestrade would ring, and he'd have clients coming and going. Mrs. Hudson would be in and out, checking on him, and commotion from the street floated up. Life was noisy as usual. But the nights, he'd noticed, were somehow both quieter and louder now. The new silence in the flat amplified every little sound, to where Sherlock could hear his every breath now, his every footstep.

He'd never noticed such loud stillness before, not with John around. When John was there, when the world quieted down, there was sometimes yelling and sometimes laughter and mostly conversations. The telly stayed on more. Even when Sherlock needed silence, John still made his own sounds of life: walking, eating, even breathing. Sherlock could tell how John's day at surgery went just by the way he breathed when he came through the door (good day, he was breathing quicker from jogging up the stairs; bad day, he was breathing evenly from walking slowly). Now, the only noise until sunrise was what Sherlock made himself. It was enough to drive a man mad, and he'd only been there for two nights.

Wonder what two years would've been like, then? a voice in his head asked, and Sherlock blinked in surprise. Nights like this, with the screaming silence. Every night, for two years. That's what it would've been like for John, whether at Baker Street or elsewhere. A deafening quiet after so much noise and life. Every sound one man could make amplified to a dull roar.

That might be…a bit not good for a person, Sherlock reckoned. That might change the way they feel about things. But why?

Sherlock rubbed his eyes tiredly. This was the trouble with emotions. Identifying the how and who of human nature was his job. A crime happened. Who did it and how? Easy enough. The why? That bit was harder. Usually he talked to John about such matters, because John could explain emotions. But John wasn't there, so Sherlock was going to have to solve this on his own.

The detective closed his eyes, going deep inside his mind and entering his Mind Palace. He kept "copies" of some of his most useful acquaintances there. Molly, for one, and though he'd never admit it, Mycroft was another. Sherlock never needed a copy of John, because John was always around in reality. The wing for information on John Watson was larger than any other place in the Mind Palace (even his section for tobacco ash), but still the real John Watson was much more useful than any version Sherlock could create internally. But without the actual living, breathing man, a copy, based on everything Sherlock knew about his friend, would have to do.

Sherlock visualized them both at 221B, in their chairs, and when John appeared he was clean-shaven (of course).

"Why am I here?" he asked testily. "You know I moved out."

"I thought it would be more comfortable," Sherlock replied.

"Ever heard of 'neutral ground'? You're gonna have a row with someone, you meet on neutral ground."

"Are we going to have a row? I hadn't planned on it myself. I only wanted to talk."

John shook his head in exasperation, and Sherlock inwardly noted he had seen that gesture far too many times. It was nearly exact.

"Honestly, Sherlock, I don't see how this is going to help anything."

"John, I need you," Sherlock emphasized his words, hoping to at least get through to his own image of his friend. "And London needs us both. The sooner I understand what happened between us and figure out how to fix it, the sooner we can get back to The Work."

"Do you think I still care about The Work?!" John yelled. "Did I seem at all interested in returning here," he gestured to the flat, "in returning to the life you left behind? 'Coz that's why I left it behind, too!"

Sherlock shook his head in defense. "I didn't want to leave it behind. I didn't want to leave you behind. I told you: I had to do it. Moriarty gave me no choice—"

"No, you idiot," John interjected. "I'm not angry because of why you did it. You know I'd come round, that I'd understand after a while."

Sherlock knew the hurt was showing through on his face. But this all being internal, it was fine for now. "That is what I thought. I thought you'd understand. I did this for you, for all of you, so why are you angry?"

John turned his head away for a moment, breathing slowly. When he looked back, Sherlock saw he was fighting tears. But that couldn't be right. Sherlock had never seen John cry before. Well, strike that: he had seen John cry at his grave once. But Sherlock had been behind John, and so he only recognized the visuals: slumped back, hand shielding face, shoulders shaking irregularly. But fortunately Sherlock had been spared from seeing John's face. So how could he know what John looked like in such a state?

"It's not why you did it, Sherlock," John's breaking voice brought him back to the moment. "It's how you chose to come back into my life."

The scene shifted from Baker Street to the moment from the restaurant a few days prior, and Sherlock could see their reunion in third person. He could see the moment John finally looked up and saw the face of his dead friend for the first time in two years. He saw the moment his friend's brain recognized Sherlock, creating a clash of information. Sherlock is dead. But Sherlock is also standing in front of me?

Before, Sherlock had beamed at John's confusion. He'd been proud of the trick he had pulled off. It turned out he'd seen but not observed, as he was wont to chastise others.

But this time, he observed as John's carefully constructed resolve shattered.

Because he knew what to expect now, Sherlock saw—actually saw—John's face go from shock to hurt to despair. Sherlock watched John look away and then back up, tears swimming in his eyes, and realized that was how he knew what John looked like when he was desperately trying not to cry. The grief was quickly transformed into anger, but the moment had been there. It had still happened.

And Sherlock was the one to cause it.

Again.

As the scene at the restaurant unfolded, Sherlock sensed Mind-Palace-John coming to stand by his side. He couldn't look over, not now. Sherlock didn't understand emotion, but he understood pain and he was currently feeling it, somewhere in the vicinity of his ribcage. In the past he might have brushed it off as a possible work-related injury. Now he could recognize it as the same pain he'd felt when he rang John from the rooftop of St. Bart's. Guilt. Regret. Sadness. He'd forgotten in his time abroad, and it'd all but disappeared the night he knew he would see his friend again.

Now he remembered the feeling, and his voice was thick when he spoke: "I didn't realize."

"You show up like that, surprise me in public, and it's like it was all a joke to you," John said softly, looking aged beyond his years even without the mustache. "Like what I went through the past two years was nothing. Like thinking every day I watched you die…that I couldn't do anything to help…that it didn't matter to you."

"It wasn't…I didn't…" Words failed Sherlock while the past played on like a film reel. Sherlock-the-waiter was rubbing his fake mustache off now, laughing at John's expression. Sherlock gritted his teeth, closed his eyes, and willed the scene away. When he opened his eyes again, he and John were back at Baker Street. Sherlock took a deep breath and finally met his friend's gaze.

"I am sorry, John. I am so sorry."

John nodded once, quickly, and his face changed. It was closer to the John he knew before—not totally there, but almost.

"If you really mean that, then find a way to say it," he said firmly. "To the real me."

Sherlock nodded. "I will. I promise."

"I won't want to listen to you," John added. "You know I won't. You'll have to make me."

"I'll find a way."

Sherlock reached across the divide and offered his hand. John met him halfway and grasped his hand firmly. A handshake for a promise. The sensation stayed with Sherlock as he opened his eyes and found himself still sitting in 221B, left alone in the maddening silence of a now one-person flat.