Sherlock didn't say a word for two days. Nothing anyone said could make him talk, and no one really wanted to. He stayed in his most of the time, only coming down once or twice a day to eat, and never at mealtimes.
The day before Mycroft had to leave, he decided he had to talk to Sherlock. He walked into Sherlock's room without knocking and sat down on a chair. Sherlock was curled up on his bed, his back to Mycroft. Mycroft considered how to go about it.
Finally, he supposed he had better just get it over with.
"Sherlock." he said. "Sherlock, are you all right?" There was no reply. Sherlock didn't even move. Mycroft sighed, then went to sit on Sherlock's bed. He didn't react.
Mycroft bodily picked Sherlock up and sat him in his lap. It was the closest he'd been to Sherlock since he was a baby. There was still no sign that Sherlock even noticed he had been moved. After a time, Mycroft spoke again.
"Sherlock. I'm leaving tomorrow. Will you be seeing me off?" Sherlock gave a tiny, nearly imperceptible shrug. It was the first indication that he was even aware that Mycroft was there.
"Are you angry with me, Sherlock?" This time, Sherlock gave an extremely noticeable nod. "What about?" Another shrug. "Is it about Redbeard?" Sherlock actually spoke, although his words were muffled.
"You're leaving and you don't even care any more about me and all you like is the government. You don't even play with me anymore."
"That's not true at all. I care a lot about you. That's why I'm here right now."
"Then why are you leaving me? I'm losing my first mate and my sea monster all in one go," said Sherlock bitterly.
"Because, brother. It's an opportunity to further myself. Someday I won't even live here, and then eventually neither will you. People grow up. Caring is not an advantage, Sherlock. All lives end. All hearts are broken. " That was the wrong thing to say. Sherlock curled up tighter and refused to say another word. Mycroft felt several drops of water soak through his pants leg.
Eventually Mycroft set Sherlock back on his bed. He covered him up, wishing he could help and at the same time admonishing himself to follow his own rule. Sherlock was always the exception. No matter how much he tried, he couldn't stop worrying about his baby brother.
As he left the room, he hesitated; then he shut the door and left.