Captain John Watson is perfectly capable of taking care of his thirst for adrenaline and battlefield. He needed Sherlock at first to get up on his own feet after being wounded, but that's just it.

Some nights John puts on a dark special forces uniform (or something like that), covers his face with a balaclava and goes after baddies, to save people who need to be saved (from abusers, robbers, rapists and other scum).

Sherlock finds out. His reaction? He desperately wants his John back to be his inspiration again, wants them to work together again. Clearly, John wants to fight crime. But they can fight crime together, like they used to! John is okay by himself though, and doesn't want to run after Sherlock anymore. They can have some cases together, as equals(!), but John is his own man. A lot of angst is very welcome, and so is unrequited (or even mutual, but maybe impossible) love. I'm okay if you give johnlock some hope though.

Bonus if the mysterious hero in balaclava gets some recognition and admiration from the good people. There are interesting rumours and speculations. People are intrigued. There are even admirers in NSY.

Can take place after Sherlock's return from being "dead".