His brother has stayed off drugs, has found a flatmate who not only tolerated him but also called him a friend, and has made a name for himself. Mycroft thought he could relax a bit, could reduce his worrying level to whatever a normal big brother's worrying level is. (When have Sherlock and I ever been normal?) Mycroft thought that only Sherlock could fool him, but there is one other man who can. He makes the mistake of letting his guard down around that man, and Sherlock is the one who pays the price.
A few days later, Mycroft receives a phone call. The call is so similar to a call he received nearly a decade ago, except this time he hasn't been expecting it. (I thought I expected everything.) His brother is once again at St. Bart's after a suicide attempt. The difference is that this time he didn't overdose, he jumped off the roof, and this time his suicide was successful.
Mycroft Holmes no longer has anything to fear.
A/N: A sequel is in the works.