I didn't manage to get Unraveller yet, but I did finally get _Deeplight_, last year's Hardinge book. Be warned - it is not nearly the light-hearted romp of the earliest ones. It is a dark story in a dark world. In the insular world of the islands, the divers and the other islanders look down on the continentals - the gawping tourists - and admire their own deep divers, who go down in primitive bathyspheres to scrounge for pieces of the bodies of the dead gods. Which they sell, because the magical content can be used. Deep divers often go deaf, so most everyone knows at least some sign language. But it's a tough life, and the main character has a problem - his best and almost only friend is toxic. When he is caught and sold into slavery he only just manages to escape the mines by using his best talent, story telling. As long as he amuses his owner, he's almost safe. Until his best friend shows up again. And his owner is up to something secret, too.
Late to the party, I know, but I finally got hold of Frances Hardinge's "Fly By Night" (2005) and am now in search of "Fly Trap" (UK title Twilight Robbery). I had already read "Well Witched" (UK title Verdigris Deep) and enjoyed it.
A very good writer for unexpected twists. I love Verdigris Deep, and can also recommend A Face Like Glaas (about an underground culture where everyone wears masks), Cuckoo Song (about changeling sisters) and possibly my favourite Gullstruck Island (about colonialism, with deep politicking, astral travelling, volcanoes, and a startling villain--it's fairly comparable to PTerry's Nation)