How fitting it was, Mycroft thought, that at their first meeting, John killed for Sherlock, and at what was to be their last, Sherlock killed for John.

If he believed in that sort of thing, he might have smiled at how fate worked out.

But he didn't. Mycroft didn't believe in fate.

He did believe in Sherlock though. And he knew just how much Sherlock cared for John Watson, no matter what John may have done.
(Mycroft could think of a few things, varying from their first meeting after his death, to what his wife had done.)

And how even more fitting it was, Mycroft thought, where they aimed.
John shot the cabbie in the heart.
Sherlock shot Magnussen in the head.

What they valued most.
What they thought would be the most destructive.

After all, Sherlock valued his brain over all else, everything else is just transport, and John was the moral compass, you keep me right, and they both went for what they valued most.

But contrary to what some might have though, those disillusioned people, John Watson was not stupid, and Sherlock Holmes was not heartless.
(Sometimes it just worked to their advantage that it was thought that.)

But Sherlock saved John because he was in love.
And John saved Sherlock because he was being clever.

Sometimes Mycroft wondered if there was anything those two idiots wouldn't do for each other.
He feared the day that would happen.
Surely then, England would fall.