The Fables are trying to come to grips with their unexpected freedom - they've spent centuries avoiding the Adversary, only to defeat him handily. Their newfound position as victors has come with a price - they have no idea what to do with the fragments of the Empire.
A few upcoming plot points raise their heads (including a tantalizing reference to a group of irritated 'second-generation' Fables and a return of the sinister Baba Yaga), but then everything is brushed aside as a new Big Bad suddenly surfaces: Mr. Dark.
I suspect, given the rather traumatic changes to the cast of Fables that take place in The Dark Ages, this is a deliberately intense collection - a rush to get everything in place so that the next act can get started. I would've preferred a long intermission.
The war came and went with surprising speed, and now, rather than exploring some of the developments that stemmed from it, we're immediately leaping into the next story arc. There's a lot going on in The Dark Ages, and rather than serving as a much-needed opportunity for the series to catch its breath, we're immediately plunging forward into a half-dozen new storylines. All comic book series seem to suffer the curse of acceleration - so far Fables had remained immune, but the last two collections now leave me doubtful.
I'm also a little perplexed by the new Big Bad. I can only hope that Mr Dark is from a myth or fable that I don't know about, rather than being a completely new creation or another one of the metafictional abstract concepts that seem to be taking over the Jack of Fables title. I can accept that analogues of Fafhrd and the Grey Mouser are somehow 'fables' (this was cute, but opens a big can of worms on what constitutes 'fable' status) - at least they're based on something. The charm (and the premise) of Fables is its creative basis on... fables. And I don't mean that in a pretentious Jungian/Campbellian way - there's just something wonderful about a series that extrapolates a universe packed with these timeless characters. The best stories in the series are those - like the very first one - that keep this concept front and center. There's a lot to work with using this characters without further, independent, world-building.
As always, I look forward to the next collection with great anticipation. I would recommend this collection - as I recommend Fables as a whole - but I'd still tag this as a rare 'average' note in an otherwise exceptional series.