It wasn't the first time Sherlock had been speechless, but it still was uncomfortable for the famous consulting detective, particularly when the situation was so painfully tense. He had considered resorting to humor but his jokes usually fell short and John didn't look ready for laughter. He had been staring at his mother in law without more than a few words for a very long time, it seemed, and all the while she just sat and played with baby Rosie, perfectly content.

"She said she was—"

"An orphan? Yes, she would wouldn't she?"

Silence.

John looked at Sherlock finally, his face clearly displaying his desperation. Of course, the fact that he turned to Sherlock to smooth an uncomfortable social situation was proof enough that he was desperate.

"Um, excuse me, but ah, why are you here?" Ah, tactful as ever, the great Sherlock Holmes had done it again.

John and his mother-in-law both turned to look at him, one looking amused and the other quite frustrated albeit still desperate. Rosie turned, too, but her expression was less telling, since it also involved copious amounts of baby drool.

"You," she nodded towards John, "married my daughter. She has since past away. But I wanted to meet you, and my granddaughter." She nodded again, as if this story was confirmed. Of course, the resemblance she bore to Mary Watson was so close that it was impossible to doubt the blood relation between them.

"Why did she say she was an orphan?" John asked, quietly. It had been so long since he had talked about Mary and Sherlock knew this wasn't the easiest way for him to do it.

"Well, her father did pass away. Well, he disappeared at least. Arthur," she smiled vaguely, "he was so sweet. But anyway, so she probably didn't know where I was. I've been incognito since he passed away."

"Because of the letters?" Sherlock asked suddenly. John closed his eyes, as if he wished Sherlock would do anything but make deductions right now.

"Yes," the woman said simply, "because of the letters, Mr. Holmes. " She put out one small hand to shake Sherlock's as if she hadn't been sitting on the floor of his living room for the past twenty minutes. "My name is Elizabeth."

"That's Mary's—" John coughed, straining as if his voice was suddenly impossibly difficult to use. "Mary's—" His head drooped and the grief that washed over him was visible.

"That was Mary's middle name. That is, the middle name she adopted."

"Mary," Elizabeth smiled, "She always liked 'Mary'." She observed John Watson for a moment before standing, stepping to his side, and wrapping her arms around him. Sherlock picked Rosie up off the floor and watched the very maternal action. To his surprise, John allowed the touch and hugged the strange woman in response, crying stiffly into her side.

"Your daughter was a beautiful person," he finally sobbed, "she was so—she—"

They sat quietly, Elizabeth holding John, Sherlock holding Rosie, and the memory of Mary Watson holding them all.

"Will you take it, Mr. Holmes?" She asked softly, turning her attention to the curly-haired detective. "Will you take my case?"

He nodded solemnly and put out a hand, into which she placed three soft letters, each inked with the same address but different names. Sherlock glanced at them and quickly identified the names as each of the members of Elizabeth's small family—each was addressed to one of Rosamund, Elizabeth, or Arthur—and he wondered at the strange sloping handwriting, as if the letters had been written in the 1600s or by some royal monarch of a long past dynasty. The letters were old, having been written perhaps a decade or more ago.

"Sit, ma'am," John said finally, pointing to the chair in the middle of the room. "You have to."