Yuletide reveal day!
I wrote
To Be of Use for qwerty, aka
xsmoonshine. The fandom is Diana Wynne Jones's The Homeward Bounders, a YA fantasy book. (The slightly revised ff.net version is
here; basically, I killed a typo and smoothed some minor narrative flow and clarity issues.)
I shall summarize the book for those of you (which is probably most of you, sadly) who have not read it: There are many, many worlds, and there is a group of demon-like beings called Them who run all the worlds as a set of giant war games, like Risk. Now and then people discover the truth and are exiled to walk the Boundaries, which means they travel from world to world trying to get Home.
Jamie Hamilton, a boy from a version of England circa 1880, is our narrator. In the course of his wanderings he meets other Homeward Bounders, most notably Helen Haras-Uquara, whose world is rather like a real-life version of Dungeons and Dragons (she's kind of a cleric equivalent), and Joris, an apprentice demon hunter who also happens to be a slave. They realize they can direct their own travels instead of waiting for Them to fling them about, and begin to fight back.
The brilliant thing about The Homeward Bounders as a fanfiction source is that it has so many possibilities -- infinite worlds to choose as settings and a lot of interesting characters who clearly had lives before they were rudely yanked out of them and will most likely continue to have interesting lives after the end of the book. But my story deals only with Joris and his master, Konstam Khan.
Joris thinks Konstam is the most amazing person in the world (and to be fair, he's mostly right), but he hates being a slave. Fortunately, Konstam reveals during the course of the book that he plans to manumit Joris as soon as he turns eighteen; he'd do it sooner but that would be illegal. (I think Konstam thought his intentions were obvious, which, clearly, they were not to Joris; they seem to have a slight culture clash over the issue of slavery.)
To Be of Use is an explanation of how Konstam and Joris first met, and why Konstam bought a slave when he doesn't seem enamored of slavery as an institution. It's also a small demon hunting adventure, because this is Joris and Konstam. (One is a rich scion of a world-famous family! The other is his slave! Together, They Fight Demons! *grin*)