A/N: I wrote this piece in response to all the fanfics depicting how much Mycroft changed in the aftermath of Sherrinford- some of them written by (ahem) yours truly.
I think it very likely that he wouldn't change much at all, in any way of significance. This piece is about a much subtler change, that comes about years later, and is probably more IC for the Iceman. Please let me know what you think!
In the aftermath, Mycroft didn't fall apart.
He didn't fall into depression. His thoughts didn't turn suicidal. He didn't wallow in guilt. He simply moved on.
He did what he had always done. Taking care of his parents. Watching over Sherlock. Even watching over Eurus. In the end, everything remained his responsibility. As usual.
In truth, hardly anything was different. Oh, yes, Mummy was fawning even more over Sherlock, but the difference was only quantitative. Sherlock had always been her favorite. She had forgiven Mycroft, or so she had implied when she squeezed his hand in Sherrinford. Mycroft was once again playing the role of the ever-dutiful son, accompanying his parents to their awful musicals, running their errands, while continuously having his ears chewed off by his mother's stream of chatter.
He had dealt with some fallout from his superiors, but ultimately, Mycroft proved to be too indispensable to really be disciplined. He had even managed to come out even stronger than before, by harping on the fact that his direct orders had been ignored, shifting the blame elsewhere, and installing better security measures in Sherrinford. He had them believing that only he could be trusted with this task, which wasn't far from the truth.
Sherlock and Dr. Watson were back to their usual shenanigans. Mycroft would occasionally visit, suffer through the lectures Mrs. Hudson would inevitably give him (usually on the importance of family, ironically), Sherlock's expected weight-related comments, and John's usual belligerent remarks. He would then take hold of his umbrella, make a dignified exit, and promptly supress all those pesky little emotions the visits stirred up.
There were the usual work-related crises. Election issues, security concerns, financial matters. Same old, same old. Anthea had finally tied the knot with her long-time boyfriend, and he had a different PA now, but she was efficient, too.
Three years slowly passed. He woke up one morning and looked in the mirror. And discovered his first grey hair.
It shouldn't have affected him at all. Mycroft knew he was aging. He was also very aware of the next step after aging. Everyone dies. Why does it still come as a surprise to some people? Yet he found himself unsettled.
He tried to analyze his reaction rationally. He wasn't afraid of dying. Was he afraid of aging? Perhaps he wasn't so comfortable with the idea. He wasn't looking forward to losing his mobility, even more of his hair, and perhaps even some of his mental acuity. The Holmes family thankfully didn't have a history of age-related dementia. In fact, the majority of the old geezers retained their full mental faculties up until the day they expired.
So what made him feel so uneasy upon seeing the discolored strand? What dangers did it portend? He didn't know. He didn't know, but he would have to find out. Gray hairs would continue to plague him, and then there would be the white ones. And if there is one thing Mycroft wasn't ready to do, it was living the rest of his life in fear.
The British Government made a decision. It wasn't an impulsive one, despite the split-second it took to make. It was the only one that made good sense.
"Hi, Charlotte, I'm taking the day off." With these words, Mycroft began a journey, one he didn't know exactly where it would lead to. He had a destination in mind, of course, but that was only the point where he would drive to. Whatever else happened might affect the way he lived for the rest of his life.
Mycroft allowed himself one impulsive decision. He lovingly loaded the supplies into his car and savored the stirrings of excitement welling up, accompanied by a frisson of fear. He drove in silence, passing through crowded cities and idyllic meadows, but barely paying attention to his surroundings. After several hours, he opened the window and inhaled the fresh sea breeze, tinged with salty droplets. He had arrived.
It took him several minutes to set up his supplies. The easel winked invitingly at him, and the paints were calling his name knowingly. He took a deep, fortifying breath and reached for a paintbrush.
The routine was so familiar, yet he could feel the rust that had set in. He carefully mixed some colors. Then he began to outline the scene in pencil. He dipped a brush, and began with broad, sweeping strokes, trying to encompass the entire picture, while not letting himself get bogged down by the nitty-gritty of the details. It was liberating, and terrifying at the same time.
He got creative with his colors, daringly throwing in some yellow in the sea's foamy green waves. He mixed, he matched, he underlined. Slowly, the painting began to take form. Mycroft had to put down his brush and knead his fingers, feeling the pain of using long-forgotten muscles. He looked out at the sea, and savored the sight of it for a moment, not with the eye of an artist, but with the eye of a man taking in the vastness of the sea, and standing small before it.
Invigorated by his little break, he reached for the tiny brushes, adding some detail here and there, painting over some minor errors, but leaving the initial feel of the bold, swirling waves. He stepped back, and then he smiled.
On the way back, he found that his smile had not diminished. He still could not predict how the gray hairs would affect his daily life, in the near future and the distant one. He didn't think his schedule would change much, though. Mycroft would never shirk his responsibilities, and always look out for his family, and his nation.
He did, however, have a notion of what those gray hairs represented. It represented the fear of losing himself. Underneath that fear, lay a much deeper terror; the one of not knowing himself in the first place.
One day, perhaps, Mycroft would deal with his fears of the world changing, dragging him along with it. For now, he was smiling with the contentment of a man who had found himself, at last.