User blog comment:Argulor/Why the subplots?/@comment-9946467-20130524231248

I admit I got some of these ideas from something I saw on TV Tropes, but still, the Ironbeak subplot is something I've felt was filler for a while. I mean, you've already got two sides to the story---that of Matthias and his friends, and that of Slagar's slaves and slavers. And really, at 446 pages long, it's the longest book of the series.