Final Sanction. Nearly everyone here has heard of and/or played it at some point. It wasn't the best mission the FFG team has ever written, after all it was only the teaser for the actual game. That didn't keep me from falling in love with the characters, setting and story though. After playing through the infamous introductory adventure a week or so ago, I picked up a pen and started writing a backstory for the characters and transcribing the deeds of our Kill-team during the mission.
The first chapter is the backstory of a few of the key characters, written from the perspective of Apothecary Lucien and is by no means finished. That said, I need some serious proofreading and constructive criticism to ensure that the piece maintains the Warhammer 40k feel and flavor.