"Your loss would break my heart."

It wouldn't be the first time. On nights when covert wars are brewing, or when the game is on, Mycroft has his age-old nightmare—more of a memory, really—of that day when he came home to a three year old Sherlock dismantling his nursery, shrieking that everything was too much, too much, too much, and Mycroft realized with horror that his brother was going to be exactly like him.

That day became the tipping point for everything else. Fast forward fifteen years and Sherlock flew through his days on a high—literally. With his normally manic personality tripled Sherlock went from deconstructing his surrounding, to strangers, to, finally, Mycroft himself. With every deduction now a pressure point, that time became a period they couldn't easily come back from.

Mycroft watched as his brother poisoned himself for years. Then he watched as John Watson arrived and, in twelve hours, did more for Sherlock than Mycroft had managed in a lifetime.

That was a loss all its own.

Mycroft sat back as Sherlock began throwing himself to the real murderers and psychopaths. He forced a smile and let his brother jump off a roof.

He let him kill a man.

Sometimes, Mycroft wonders how many times he can lose Sherlock before his heart well and truly breaks.