"A Longer Haul" is rooted in a few key points, and I guess ultimately each one got its own part in this three-part story (which ended up substantially longer than I first envisioned).
In part 1 I seized upon a bit of throw-away dialogue during a visit to romanced Kaidan- "you weren't there when I woke up"- which to me strongly implied that 'Shenko' got physical in their relationship before the 'big romance scene' en route to Cronus, and I wanted to expound on that because I felt like, having waited so long for it to happen, it would have been nice to have seen more detail. Part 1 ends with imagining the 'controversial' last 10 or 15 mins of the canon story from Kaidan's POV to try and answer that big, burning question of how (and why) the ground team ended up back on the Normandy and in-flight when the Crucible fired. I wrote this before the EC released and felt kind of vindicated because some of that new content seemed pretty close to what I thought had to be the obvious explanation to how the squadmates got back aboard Normandy and why she was 'running' from the fight at the end. One could read part 1 and stop if they wanted to imagine everything after the game differently.
In part 2 I started to take increasing creative license, first in order to give my less 'doom-and-gloom' answer to some of the post-ending questions about "wouldn't destroying the relays kill everybody like in Arrival?" and "even if it didn't, isn't everyone screwed now anyway?" and "how can synthesis be anything but the annihilation of individuality- and therefore a terrible choice?" And I tried to show the ending's very personal aftermath for Kaidan, then introduced some decidedly non-canon material (ie. an ancient-but-'new' race that serves as a counterpoint to the asari and helps rationalize the protheans' interest in Thessia) to start to dangle a thread of hope for a happy ending after all.
Part 3 is the story's fruition, the "happy ending" that I so badly wanted and had to write some backflips in order to reach.
Throughout I realized a couple things as I was writing- it's really sort of a story of Kaidan inheriting Shepard's spotlight for a while, and even culminates in him having to make his own big choice about the future. But what alarmed me a little was when the characters really 'came alive' in my head and I found I wasn't sure that I could honestly write Kaidan doing what I wanted him to do. Try as I might I couldn't contort him into taking the easy way to the happy ending. There's a conversation that sort of serves as my own 'confessional' to its effect on my writing process. Thank goodness for the other characters and their various motivations, sometimes it's easier to let them give the 'push' the story needs and wants! :)
I've started a completely original sequel to this story but I'd still appreciate constructive reviews so that I can try to capitalize on what readers found most successful in this work. Most helpful to me would be to know what people liked best (scenes, portrayal of characters familiar and new, plot points, style, etc) and what people didn't find worked that well so I can try to hedge out the stuff I didn't do as well.
To sort of 'enrich' the text I've tried inserting the URL for one hosted image as an illustration for the scene (I hope that's allowed, if it isn't I can remove it) and I've put in some "soundtrack cues" with suggested music to accompany- I know, it seems a bit pretentious, feel free to ignore them, but some readers might enjoy a 'score'. I'm not even sure they 'stuck' anyway, I suspect some kind of automated filter plucked them out. :-P
Lastly, I finally figured out how to format/publish the three parts as separate 'chapters' so hopefully that'll make it a bit less daunting a wall of text to read.
[Updated with one new scene, 1.8, in the first part as of 2012/06/08. I realized I hadn't given the post-Thessia/pre-Horizon time much attention and I wanted to.]