** spoiler alert ** 
 'A book must be an ice-axe to break the sea frozen inside us' - Kafka 
 It's this quote that Geraldine McCaughrean credits with planting the seed of this novel. I wish I had read that quote before reading the book (it was included in the afterword on the ebook). It pretty much encapsulates the experience of reading this novel. 
 Sym is quite the most interesting, unusual, complex character. And yet she's almost impenetrable a lot of the time. Except through Titus. Oh, Titus! He couldn't possibly be real, could he? be nothing but a figment of Sym's imagination. A pretend friend. Whether he's more than that and, if so, how much more depends on the reader. But he's so important. For me he's the heart of the story. Without him it would be totally cold and beyond my grasp. 
 I found most of the other people around Sym quite repulsive. She makes excuses for them all, but it's hard not to see them all as nasty parasites with harmful obsessions. 
 A lot of the events of the book are so incredible it's hard to credit them. But given the scope of Antarctica - an inhospitable, alien landscape, brilliantly described in the book - it works. I can believe a lot of things are possible there that wouldn't be anywhere else. 
 I did get a lot of the twists and turns before they happened, but I think that Sym did really, so I don't see that as a shortcoming in the writing. 
 Overall I thought this was a very good if rather unpleasant and uncomfortable read.