A/N: Most of my information about Holmes comes from reading the stories, but also from Check it out if you want more information.
"Before I departed Brighton I received a telegram from Mycroft," Katherine said as she sat down in a seat by the window. "He sends his best, and wanted me to inform you he might drop by."
"That would be brilliant Holmes," I said, turning toward him. "It would be a sort of family reunion."
"I shall believe it when Mycroft knocks on the door. You know Mycroft-when he's not in his office, he's either in his rooms or at the Diogenes," Holmes remarked from his post by the window.
I picked up the newspaper on the nearby table, and then remembered I had already read it. I stood up, and walked over the bookshelf. Though I had planned on taking a novel, I changed my mind, and instead picked up a medical volume Holmes had recently purchased.
"What are you working on, Sherlock?" Katherine asked, standing and walking toward the table on which Sherlock carried out his experiments.
"Nothing at the moment," he replied, glancing over at her.
"Is there anything under the microscope?" she asked, her eyes scanning the table.
"Yes, some medical slides of Dr. Watson's." I looked up from my book. Holmes had turned from the window and was watching his sister. His face had its normal expression, but I could sense some amusement. We watched as Katherine looked through the lens, focused the microscope, moved the slide, and focused the microscope again.
"Fascinating," she murmured, looking up.
"Did you learn about microscopes in school, Katherine?" Holmes asked.
"If they would've allowed us to use microscopes at school I would not have minded it so much. In Brighton when I stayed with Maria DeBourgh and her parents, her older brother had a microscope. He was studying to be a doctor as his father and older brother were. I helped him study for his exams and he taught me about biology and afflictions of the human body. He said I was quite brilliant…for a girl." Here she stopped and rolled her eyes.
"Yes, I would imagine you are," Holmes said. He then bestowed upon his sister a rare smile. "I would imagine there are some more slides over there if you ever care to look at them, and Watson and I have several medical volumes in our combined collections if you would ever care to read them."
Katherine began to thank him as the study door opened and Mrs. Hudson announced there was a visitor.
"I knew it wouldn't be much longer," I said, looking over at my friend.