Read Even Hand.
LOVED IT.
Loved smart!Hendricks and how awesome Gard was and the fact that Marcone has claymores and the bullet that killed Nelson at Trafalgar. Adored the references to Harry, because its canon now how much John thinks about him. :D Adored Justine and the three idiots at the beginning of the story. Really enjoyed Marcone killing people coldly. Also loved that Hendricks hates to kill but is damn good at it, because John taught him how to be. Also love how no matter how much Marcone tries to make us - and everyone else - think he has a heart of stone, he knows he doesn't, he knows his own weaknesses, and if he's not precisely okay with that, at least he's honest.
Absolutely loved everything about it. Very very fun.
Gonna go read more fanfic now. Need some Harry/John schmoop