While the travelling kept up a fast pace I didn't get a sense of place from anywhere mentioned. Some vague descriptions just whetted my appetite to read more about the regions. Amy, David and Simon really didn't come to life for me but the story kept me reading. It's a gruesome story and with not enough details left out sometimes and vaguely twitch-making pseudo eugenics science thrown in for good measure. It did keep my attention and David's mystery was what kept me reading but I think the author was trying too hard to impress.