So, I went to see Phantom of the Opera in the West End just before xmas with my best friends. Then today I watched Les Mis at the cinema, which reminded me of this series, which led to this fic (since I'd already done the Les Mis one).
Slightly different format to the others, because I couldn't see Sherlock taking time out from being undead to go and watch a musical.
Italics=quote.

Sherlock was trying not to think. He didn't look like himself as he walked through the streets of London. That was the point. He had his head down, shoulders hunched. He'd shaved his hair away. He hadn't expected to feel so unlike himself. He just didn't want to be recognised. Really he should have taken up Irene's offer. Made a clean break. Maybe he still would. But it was difficult. It had been so much easier when he just didn't care.

He merged with a crowd emerging from the theatre. His new persona fit this clique well, and he was immediately absorbed, invisible. A ghost on the street.

A group of young women were babbling about something just in front of him and he joined the back of their little clan. It was easy. Everything was easy now he didn't have John and his moral sensitivities and ridiculous quirks to deal with. The fridge was a perfectly suitable place for body parts, and why shouldn't Sherlock say exactly what he thought? Everyone knew he was cleverer than them anyway.

This was a good plan. He hadn't made a mistake. He hadn't. He'd had to die. He'd had to make sure the others would be safe.

"It breaks my heart every time. The way Eric is so in love with her, but he's too dangerous for her to ever want."

"Eric?"

"Sorry, it's what the Phantom's called in the book."

"It was a book?! Dude, you've just shattered my worldview."

Sherlock listened intently. Mostly he wanted to distract himself from his own thoughts. But it didn't help. It just sent his brain spinning off on a more depressing tangent. Shattered worldviews were something he was all too familliar with.

John. He loved him. He did. But John was better off without him. He was dangerous, unfeeling, asexual. A high functioning sociopath. Besides, John was straight. He needed someone, a woman, who would take care of him, care for him.

Not someone like Sherlock.

One of the girls, a plump bottle blonde, leaned heavily into a skinny brunette.

"Lightweight," the skinny brunette said, smiling.

"That's what I have friends like you for." She smiled back, and then started singing quietly. She didn't seem completely drunk, but she was definitely tipsy. "Think of me, think of me fondly, when we've said goodbye... remember me once in a while please promise me you'll try..."

I don't have friends. I only have one.

Would John still think of him in a year's time? Two? He had no idea how long it would take him to track down the remnants of Moriarty's organization and shut them down. It could take him a lifetime. Would John still care when he got back?

Maybe it wasn't too late. Maybe he could go and find John right now and explain why he'd done what he'd done. Invite him along on the mission.

"I think my favourite song was the one that was part of the opera the Phantom wrote," the redhead said.

"Which one?" a second brunette, this one generously curved, asked.

"You know..." she hummed a few bars.

"Past the point of no return, no backwards glances, our games of make believe are at an end..." The tipsy girl sang.

"Yeah, that one!"

Past the point of no return. That actually summed up Sherlock's predicament nicely. It was certainly too late. John would never forgive him for what he'd been forced to do.

"Masquerade, paper faces on parade. Masquerade, hide your face so the world will never find you." The drunken blonde (not speckled this one) abruptly segued into a different song.

It sounded heartsick to him. His fingers automatically began picking the chords as though he was holding his violin. It was certainly bittersweet. He preferred it to the other songs she'd sung so far. He forced his fingers to still and then reached up and ran a hand through his close cropped hair.

He'd passed the point of no return. No turning back now, he'd committed to the masquerade.

"Take me home, I'm drunk."

"Of course, hun." The group of girls kept walking, but Sherlock didn't. He slowed and then stopped, turning and faking interest in a window display so he wouldn't seem conspicuous.

"Then say you'll share with me one love, one lifetime. Let me lead you from you're solitude. Say you need me standing here beside you. Anywhere you go, let me go too," the brunette sang affectionately to the tipsy blonde, the other brunette and the redhead laughed.

"Say you'll share with me one love, one lifetime. Say the word and I will follow you..." Sherlock saw the blonde lean her head on the brunette's shoulder as she sang back. "Share each day with me, each night, each morning, say you love me..."

And with that they moved out of hearing range, and Sherlock was left standing alone amongst the crowds of Saturday night London.

He was one, unseen, amongst the multitude.