I'm unfamiliar with all these characters (except, of course, Nanami), having stopped watching New Who quite some time ago (right after Donna was introduced, IIRC) -- is Strax also from there? That was the only thing that threw me for a loop.

I liked the atmospherics of the Victorian-period setting. It's got that "well, of course they found Weird Shit while digging the Underground" vibe that makes for the best cryptohistory.

Given just how unexplained the Fleet of Fog is according to H2G2 (inaccurate as that may be), I have to wonder whether the item Miss James is offering really is the item the Castellan told Nanami to look out for.