Originally Posted by DNA-1842
I can see how he would have, because not only did he have that story, but he had to very quickly dispel the secrecy surrounding River. I mean, when they left off in the series River was just a traumatised young girl, with strong hints of unusual powers. And Shepherd Book had no backstory at that point, which would have been revealed!
Never getting to the bottom of Book's past was a big shame about the series and obviously not able to be worked into the film either.
Someone on another thread mentioned that Whedon was supposed to be writing a comic book that would cover some of the untold stories of Firefly but I don't think it's near publication.