The Glass of Time is a sequel of sorts to The Meaning of Night. Set in 1876, twenty-two years after Meaning of Night ends, the book begins when Esperanza "Alice" Gorst goes to Evenwood to (ostensibly) become Baroness Tansor's lady's maid. In reality, she's been sent by The Powers That Be to spy on her employer, for reasons that Esperanza will not be told until later.
We first met Baroness Tansor when she was Emily Carteret, engaged to Phoebus Daunt, the poet who was murdered twenty years before The Glass of Time opens. She still harbors feelings for her former flame, however, and one of the things she has Esperanza do is read from Daunt's work. She also has Esperanza run mysterious errands into town, much to the suspicions of Evenwood's housekeeper. What unfolds is a web of deception, lies, and, yes murder--not much more than that about the plot I'll say, only because I don't want to give anything away.
The Glass of Time has been one of the books I've been anticipating the most this year, and it didn't disappoint. Cox's long-winded, Dickensian style won't be to everyone's taste, but I really like his mode of writing--it sucked me right in from start to finish. His prose is descriptive, and his characters unusual and interesting. In Esperanza, Cox finds a bright, fresh, and new way to tell the story of the Tansor family. Cox's depiction of Victorian England is never contrived, like so many books set in that period and written lately are--another thing I loved about The Glass of Time.
Another thing I thought was excellent was that Cox (for the most part) got rid of the fiction that this is a "confession" edited and annotated by someone else for publication, using the convention of using footnotes to explain various passages. The Glass of Time is therefore that much more readable, making it only about 580 pages (the same length its predecessor might have been without footnotes). The reader figures out a long time before Esperanza does what's really going on; but the fun of the book is following Esperanza's journey. "I couldn't put it down" is such a clichéd sentence, but in this case... I really and truly couldn't put this book down.
Although Cox mentions events that took place in The Meaning of Night in this book, it's not entirely necessary to read it beforehand; a newspaper "clipping" about 130 pages in recaps the bare-bones storyline of The Meaning of Night. However, I would strongly suggest reading that book at some point--aside from its footnote problem, it's just as good as its sequel.