It's a frosty morning in January. Mycroft's room is cold, just like Sherlock's fingers on his microscope. Mycroft sits nearby with a book in his hands, sending Sherlock looks from time to time. Just to keep track of his movements.
The eight year old twists the coarse focusing knob and stares through the ocular lens. Sherlock has been sticking himself in the finger a couple of times this morning, and is now examining his own blood thoroughly.
'Mycroft?'
Mycroft's gaze stays on Sherlock a little longer this time, before he returns his gaze to his book.
'Yes?' Sherlock is quiet for a few seconds. Their breaths are the only sounds that fill the big room.
'What is the definition of friendship?' he asks, and turns his head to study Mycroft across the room. Mycroft answers as if reading it directly out of a dictionary.
'It is a bond of mutual affection, typically exclusive of sexual or family relations.' Sherlock doesn't have any of those, he quietly muses to himself before voicing his second question.
'But is it important?' Mycroft finally looks up at Sherlock, and he narrows his eyes.
'Caring is not an advantage Sherlock,' he tells his little brother for the first but not last time and holds his gaze, as if making sure his wise words have come across before turning his attention back to the chapter before him.
'Love then. Is it important?' Sherlock asks, curious as he is.
Mycroft doesn't answer.