I am thoroughly used to seeing all sorts of odd characters consulting with Holmes, but much less used to encountering someone I knew already.

"Dr. Tam!" I exclaimed upon entering the sitting-room.

"Dr. Watson. It has been far too long," the young man said, rising to shake my hand. We had never been friends - his arrogance and coldness rivaled Holmes' - but I had respected him even as my colleagues resented how easy every aspect of medicine seemed to come to him. He was dressed very neatly and stylishly, with the unusual touch of a silk waistcoat embroidered with looping dragons.

Holmes looked from one of us to the other. "Dr. Tam, you appear too young to have been at school with Watson and then to have spent, oh, five years in the Orient studying their more exotic methods, predominantly in China. This points to a hereditary precociousness shared with your sister."

"Sister?" I murmured, perplexed as I took a seat across from Holmes.

Holmes tilted his head towards the window, and with a start I noticed a young woman, more a girl really, a slip of long muscle and sinew dressed in a loose-fitting gown and bare feet. She turned her face to me with a simultaneously vacant and piercing smile. "Soldier and a doctor too, a faithful friend and something more. You guard the dark and hold the candle though you're flickering yourself."

Her voice was sweet yet it chilled me thoroughly. Her dress and manner spoke more of a changeling than a human youth.

"Dr. Watson, you know me, and Mr. Holmes, you have no doubt deduced a fair amount of my character and circumstances. So you will fully understand my meaning when I tell you that Rivera, called "River" by friends and family, until recently made me seem an idiot child by comparison. Her intellect dazzled us from the moment she began to speak and taught herself how to read. Science, philosophy, mathematics - all these subjects unlikely for a girl-child to reach proficiency in came as naturally to her as dance, which she loves just as much."

"The Inspector only dances alone," Rivera said with a laugh, weaving her fingers through her long and unruly black hair.

"I believe that a child that shows aptitude should be encouraged and educated, regardless of sex, and I was able to convince our parents of this. We sought out a school that would share such views and allow Rivera to make use of her mind. And then..." here regret and vulnerability showed in his face and voice, something previously unknown in my dealings with him, "her letters to me became strange. Garbled. Disconnected. They were utterly out of character, and I began to suspect something was wrong."

Rivera was now curled at Holmes' feet. He did not seem to mind the impropriety. "Violins and science. You should stop injecting. Drugs are bad for your health. Your companion doesn't like it."

"How does she...?" I blurted out, but Holmes silenced me with a look and steepled his fingers, nodding to show Dr. Tam he was listening.

"I realized it was a code, and when I finally broke it I found the message that there were surgeons...chemists...hypnotists...I have no idea what else...driving her mad. Playing with her brain. Making her into something else. Against her will. And they were doing it to others."

"Simon?" she quavered, shivering and looking about wildly, as if the enigmatic calm she had previously exhibited was a thin layer over a whirling storm of fear.

Shedding his own sense of decorum, Dr. Tam crouched on the floor and gathered her into his arms. "It's all right, River. These are kind men. They will help us."

"Two by two, hands of blue. Two by two..." here she began to weep. It would have taken a harsher man than me not to be affected, both by her mental ruination and her brother's tenderness.

"My father was unwilling to believe this conclusion, calling it a wild theory born of too much opium in foreign climes. He was unwilling to recall River from the school. The considerable tuition expense was non-refundable. When I attempted to visit her I was met with refusal and hostility under trumped-up excuses. After a lengthy and costly investigation, I established that a secret society was using this school as a front for unknown machinations, but no more than that. I managed to break her out - it truly resembled a prison rather than any type of educational institution - but I am now disinherited and at a loss for how to seek justice."

"Could you not simply show your sister to your father and prove your case?" I asked.

Tam sighed and shook his head. "I received a threatening letter stating that if I take this tale to my family or the police, I will be killed and River will simply be taken again. Having seen the scope of their operation, I do not doubt that they are capable of such."

Holmes took a deep breath. "A remarkable story, and however improbable I know you are telling the truth. What exactly do you wish from me?"

"I need help finding what was done to her, and why. Only then can I hope to heal her. In addition, there were many other young men and women imprisoned there, and I would not like to simply leave them to their fate. I cannot pay you very much. I am supporting myself and my sister solely by my own practice, which has been difficult to establish due to my need to work under an assumed identity."

His having made no mention of regaining his fortune or in any way making himself more comfortable increased my admiration of him.

Having spoken to Tam, Holmes turned to Rivera. "My dear, what can you tell me about myself?"

She untangled herself from her brother's arms and stalked about the room, her hands behind her back. "Bohemian moods. Cocaine a bit, tobacco a bit more, frustration and boredom most of all. You see through bodies and into souls with the little hints of day. He is your only true friend. You have a fear of closeness, of touch, of having dependency on anything but the two pounds of gray matter in your head. You're not very nice to the dog, but then you're not very nice to anyone; there's a difference between being nice and being good." Suddenly she switched her gaze to me. "Semper fidelis. You will have to learn that you can share."

"Enough, River," her brother said softly.

She laughed, girlishly. "Don't ask if you don't want!"

"This case interests me sufficiently that I am willing to be paid in kind rather than in money," Holmes concluded, rising to his feet and shaking Rivera's hand as if she were an equal.

"What is your price, then?" Tam asked, raising an eyebrow.

"If your sister would be so obliging as to help me solve a few other cases I am having trouble with."