Something along the lines of you were the head or 2nd in charge of an established chapter, they were all ambushed and killed leaving you the sole survivor on a quest for vengeance dashed with a bit of betrayal while you rebuild the honor of the guild.

Assassins Creed: Tinker Tailer Solder Spy

after your entire network of agents is wiped out by the KGB, you return to Britain with your tail between your legs, assigned to mope around the office as an assistant to aging pedantic superspy George Smiley. use stealth to penetrate the inner recesses of filing rooms and sneakily put one file inside of another file so that no one sees you looking at a file you aren't supposed to have. Drive your pointlessly ostentatious vehicle back and forth between the Circus and Smiley's house, impressing no one. Experience a full day/night cycle and complex npc behavior patterns in the background or through the window as you sit in Smiley's dingey hotel room while he bounces various theories off you.