This takes places somewhere in between the ending of Firefly, and the beginning of Serenity. I wish I'd read this before watching Serenity, as it does explain a few things (for example: where Inara and Shepard Book were at the beginning of the movie). Basically, though, this is just an extra episode to the TV show, but without the same spark of it being acted by the amazing talent.

They tried cramming a bit too much in such a short space. Most of the time is spent on the action of the mission, and very little of it deals with the characters and their motives. Still, it was something to fill the gap between the show itself and the movie, and it really reminded me how much I miss the fun quirkiness of the Firefly universe.