It was late at night. Sherlock Holmes stood in front of his information wall for a particularly difficult case (locked-door triple murder) with Charlotte Grace Watson in a harness, asleep, on his chest. John and Mary were on a date, so they had left "Charlie" with her godfather, Sherlock. He was interrupted from his musings when he heard Mrs. Hudson open the door and murmur a conversation with Lestrade at the door.
Slow footsteps, hesitant. Not here for information on the case. Bad news. Sherlock quickly deduced as Lestrade climbed the stairs to his flat.
Sherlock whirled to face Lestrade as he opened the door slowly. "What is it? You're not here for the case; you know I'd tell you if I had any new information. You know I would, that much has changed since my return," Sherlock insisted as Lestrade opened his mouth to protest that idea, "So, what's happened?"
Lestrade took a deep breath and said, "John and Mary are dead. Their cab was hit by a drunk driver on the driver's side in the back. Mary died instantly, and it seems that John bled out. The cabbie and the driver are seriously injured. I'm so sorry, mate."
There was a ringing in Sherlock's ears. His best friend was dead, along with his wife, and Sherlock, for once, didn't know what to do. He could tell that Lestrade was chocked up, but all Sherlock felt was numb. Charlie stirred in her harness, and a realization hit Sherlock like a ton of bricks falling after a bombing. He was now this tiny baby's guardian. Her parents were dead, and she would never truly know them, all she would remember was Sherlock.
"What do I do?" Sherlock asked, but it seemed that more time had passed than he thought, and Lestrade had left. There was a note on the coffee table from him saying, "I'll be back later to talk more about funeral arrangements, and … other things. –GL"
Sherlock, unsure of what to do, stared blankly at his information wall. He suddenly felt the urge to tear it all down, to run into the London streets and never look back, to forget the best years of his life. He knew he couldn't, the presence strapped to his chest reminded him of that, so he settled for taking Charlie out of the harness and setting her gently on the sofa before taking the harness off. He then picked Charlie up again, laid on the couch, and placed her back on his chest. Then, something completely unexpected in any other situation happened: Sherlock cried himself to sleep.