Sussex Downs - Summer 2066

The first time River Song would meet Sherlock Holmes would be the last time he met her. Sherlock was nearly ninety at that point. John Watson had left him alone the year previous. Aside from John and Mary's daughter, the only one of his old friends still alive at this point was Molly Hooper-Wilson, happily married and spoiling grandchildren in a town not too far away. Mycroft had been gone for years already. Lestrade and Martha Hudson the same. Life moved on, whether those left behind wanted it too or not.

But Sherlock wasn't really alone. His mind was as sharp as ever and the memories he could pull up in his head were many. Because as his mind continued, his body was failing, slowly shutting down. It was fine. He never expected to live long without John Watson anyways.

Meeting River Song would be completely by chance. An accidental encounter. She had assured him that he wouldn't have to do anything out of the ordinary to ensure it happened that late summer day.

At the moment, Sherlock was in his gardens, he'd taken a rest on the bench nearest the beehives. To keep his hands busy, he'd brought his old violin out to play outside. He nearly insisted the bees were partial to it, at least to anyone who came to see him. The air was warm, the sun peeking out from behind the clouds. It was a beautiful day.

There was a familiar zapping sound, followed by the appearance of a curly haired woman. Sherlock's lips curled into a smile but for the moment he went unnoticed by her as she fiddled with the vortex manipulator on her wrist.

"Twenty-first century Sussex? Now I know I need to fix this thing again. Cheating little Zel-" As she turned, she noticed him on the bench and stopped. She flashed her signature smile. "Oh hello."

Sherlock regarded her in a calculating way, his hands stilled on the strings of his beloved violin. "Interesting."

"Of course it's interesting. It's me." River said unashamedly, with a brush of fingers through her hair. "Now, if you'll excuse me…"

"You're more than welcome to go, but I'd like you to stay and hear something." Sherlock said, bringing the violin to his chin. "I think you'll like it, River. It's a song to remember."

Her pink lips were smiling, curiosity in her eyes as she looked over the man she didn't know yet. His movements were slowed with age, thin fingers riddled with loss of dexterity and arthritis. But if this was one thing he was determined to keep, he would.

The notes that hummed from the old instrument were clear, the melody neither simple nor exceptionally complicated. Soft and slow, enigmatic, and just a bit flirty. It started low and gradually moved up the strings to the high notes. Sherlock's eyes closed after a bit, muscle memory guiding his fingers and his bowing arm. He didn't need to watch River's face as he played, he knew exactly what she was experiencing. He played the song he wrote for her, over eighty years in the making. His thoughts drifted from the very first time he'd seen her, that nothing more than a very distance memory of images and smells. His thoughts drifted to the nights spent in quiet conversation. Of John asking questions. Of adventures had together via the currently dysfunctional vortex manipulator. And all those memories he'd written into music.

River Song was a muse, and this was Sherlock's final song for her.

The inspired song came to an end eventually, the melody enough to get lost in, so it was difficult to say how much time had passed. And as Sherlock pulled the last long note out of the instrument and then lowered the bow, he released a deep sigh and opened his eyes.

River was smiling, the light in her eyes was twinkling curiosity and fascination. He liked it when she looked like that. Like after she'd joined him on a case, or when she took him to another world. Adventures that were now only fond memories.

"That was beautiful." She said, genuinely interested and completely in awe. "Why?"

"Because you, River Song, inspired that. And I wanted the chance to play it for you again."

"Curious." River was very interested, but there was a certain amount of knowing. "You're not going to give too much away, are you?"

"No. Not yet. You'll find out. This gives me the chance to be one up on you." Sherlock returned with a smile. Age and reflection had softened him. And he was quite sure this was the last time he'd see his oldest friend. "Spoilers."

"How exciting." River exclaimed in the usual way, her blue eyes sparkling. "If the music is anything to go by, I think I'm very much going to like you."

Sherlock stood up, his cane in his right hand to support him, his violin case in his other. His eyes, sharp as ever behind wire frames, scanned her as if memorizing every last detail all over again. "Goodbye, River Song. I think you'll enjoy what you're headed towards…." He turned away, facing the western sun and breathing in deeply before he finished. "By the way, the name's William Sherlock Scott Holmes... Could be dangerous."