DWJ fans will notice much that is DWJ-ish about Hardinge's work, especially her second book, Verdigris Deep, which reads eerily like one of Jones's earlier books (say, Wilkins' Tooth or The Ogre Downstairs). This latest is less obviously Jonesy, although the Epilogue may well make you think of Power of Three. But Hardinge was not a Jones reader, apparently, so perhaps that says more about my own limited reading than anything else.
Hardinge specializes in extravagantly baroque fantasy worlds, with plots to match. I'm not going to attempt a summary of this one or get too spoilery, but there are some wonderful touches, such as the Grand Steward, the ruler of Caverna (the underground city where the book is set), who daren't sleep for fear of conspiracies, and so has trained the left and right halves of his brain to take it in turns to run the city while the other rests: one ordered and logical, the other instinctive and creative, and each with its own set of court favourites. Then there are the Cartographers, obsessive mappers of the city whose compulsion has driven them to infectious, glossolaliac insanity. Hardinge does a lot too with the eponymous conceit of the book, that the inhabitants of Caverna are born without the capacity for facial expression, and must learn Faces in order to express themselves. The lower class drudges are taught only a few faces, all of them expressions of deference and cheerful humility suitable to their station, while the rich can hire one of the city's Facesmiths, who with the aid of their Putty Girls design and model the latest facial haute couture. As this suggests, there is a lot in this book that has application to our own world's follies and injustices, although it doesn't read like an allegory.
Hardinge is an excellent prose writer, something I meet rarely enough that I feel the need to mention it. As a cheese lover, for example, I was struck by this description of the effect of eating a morsel of Stackfalter Sturton, one of the delicacies concocted by Caverna's Master Craftsmen:
It burst apart, and it turned out that it had always been made of music. Not music for the ear, but notes of pure soul and haunting memory. She had no body, and yet she sensed that her nose was a cathedral where a choir was singing full-throatedly, and her mouth a nation with its own history and legends of staggering beauty.
It's not a perfect book. Hardinge's plot is a wonder, but she has found no better way of conveying some of its finer points than to have the villain explain the details of their machinations even while locked in mortal combat with our heroine - a cliche, but no more plausible for that. Again, with my worldbuilding hat on (and very pretty it is too, broad brimmed and fringed with stars), I wonder whether even the passage I quoted above quite makes sense, given that the person being reminded of a cathedral lives in a world where they don't exist.
Anyway. I didn't actually set out to write a review, so much as to note that A Face Like Glass is another to add to my collection of Plato's Cave books. I was thinking of writing an article on these at some point, starting with C. S. Lewis's The Silver Chair. There are quite a lot of them - books where the Cave is all that the protagonist has ever known (or at any rate can remember), and they discover over the course of the story what lies beyond the veil of illusion. They aren't all set in caves: Lois Lowry's The Giver is a classic Cave book. Even DWJ's The Homeward Bounders qualifies, given that the protagonist muses at one point: "For a while after that, I went round seeing all worlds as nothing more than coloured lights on a wheel reflected on a wall. They are turning the wheel and lighting the lights, and all we get is the reflections, no more real than that.” It's all in Plato, Jamie - what do they teach them in these worlds? Arguably, Forster's Marabar caves are a kind of nihilistic inversion, in which people go from the outer world into the cave, and find that nothing is real (or at any rate meaningful). I suspect there are many SF books with plots that turn on this idea, too.
Maybe it's just too widespread a trope for useful discussion? Should I confine myself to the paranoid fantasies, perhaps? One thing Plato never explained was who had set things up like that, or why - an inviting omission. I suppose we have to include everything from The Truman Show to The Matrix, even so.
Ah, how can we map the caves? Is this an article, a book, or a endless quest worthy of a Cartographer?