From zanganito: Icicles

Sherlock Holmes was bored, something which never boded well for the 221B living room. With this in mind, Watson suggested he revisit some of his unsolved cases. As one might imagine, they were few and far between for a mind so brilliant as Holmes's, but Watson hoped it might keep him occupied at least until he returned from that day's rounds.

He arrived home that evening to a very despondent flatmate.

"No luck?"

Holmes was sprawled on the sofa, plucking his violin discordantly, entirely ignoring the mess of papers scattered on the floor beside him. "No. I have been over every detail, three times. It is infuriating."

Watson sat in his armchair, grateful for the warmth of the fireplace after his long day of traipsing about London. "A patient of mine gave me a riddle today. Would you like to hear it?"

Holmes sighed. "If I must."

"A man is lying, stabbed to death, in his chateau during the dead of winter," Watson recited. "The only clues to the mystery of his death are an open window, and a cup of bloody water at his bedside. How did he die?"

Holmes thought for a few moments. "I assume the manner of death is linked in some way to the clues you have just stated?"

"I did say that they were the only clues to the mystery," Watson replied, bemused. "You do understand how a riddle works, don't you?"

Holmes glared. "Yes, I understand. But in a real case-"

"This isn't a real case, Holmes. Now stop stalling and give me your best answer."

Holmes lapsed into thought for a few moments more. Then, his eyes alit.

"I have it! He stabbed himself with an icicle, and dropped the icicle in the cup at his bedside."

Watson smiled. "Well done. My patient had to tell me the answer in the end, I couldn't solve it before my next appointment."

"Hold on." Holmes raised a hand for silence, as he often did when his mind was whirring over a piece of new information. He leapt to his feet and scooped up the papers, sifting through until-

"Aha!" Holmes's eyes scanned the page he found intently. Slowly, beaming, he looked up at Watson. "My dear fellow, I do believe you have just helped me crack this case."

"I have? How?"

"The murder weapon was an icicle!" Holmes exclaimed. "Back on with your coat Watson! We must get to the Yard immediately!"