Disclaimer: I don't own Sherlock.

John came home one day in a good mood. It was bright, sunny, and had been an easy day at the clinic. He felt like nothing could ruin his day. That's when he stepped into the flat he shared with Sherlock Holmes.

Sherlock stood in the middle of the room. His hands were covered with latex gloves which had turned red, and two large vats stood in front of him. They were full of a red liquid. Perhaps the strangest thing was the amount of white tee shirts, neatly folded in stacks on the couch. For a little while, John stood stunned. Then he asked, "Sherlock… what are you doing?" Sherlock looked up. "Oh, John! Hello! I'm tie-dyeing some shirts with blood and some with red dye. I'm looking for the differences between the colors." he explained cheerily. John had stopped listening at blood. "Sherlock… where did you get enough blood to dye shirts?! Why are you tie-dyeing shirts with blood? Have you got any on the carpet?"Sherlock rolled his eyes. "Honestly, John, it's not a big deal! I got the blood from St. Bart's. It's for the case-you remember how the dentist we spoke to had a strangely large amount of red tie-die shirts? I believe he is the killer, and tie-dyed his shirts in his victim's blood-hence, this experiment. Also," he added, "I've been careful not to get any on the carpet. Mrs. Hudson would definitely kill me otherwise." Slightly relieved that his flat mate wasn't a vampire/serial killer, John walked over and peered in the vat, seeing several rubber-banded tees. "So, what's the difference so far?" "I've hung some outside to dry; let's go see them. Wait here a moment!" With that final remark, Sherlock took off his gloves, tossed them at John, and sprang upstairs. He returned with a notebook covered in red handprints. "Sherlock," John said very quietly, "Do not throw blood-covered latex gloves at me. Ever." "Not good?" "Really not good, yeah." Sherlock didn't look repentant at all, but shrugged and said, "You didn't get it on the carpet, did you?"

John sighed and closed his eyes. When they were open again, Sherlock had already sprung downstairs. John followed.

Later that day, after the killer had been brought in, John had went back to the flat to find that all the tie-die shirts were gone; he thought nothing of it.

For Christmas that year, everyone Sherlock knew received a red tie-die tee shirt. No one really knew why John was laughing his head off, why Sherlock was smirking, or why those who Sherlock disliked received tees with a slightly different hue of red.

Do you think Sherlock would have given his friends the blood shirts, or his enemies?

Prompts for future experiments welcome! Please review.