Lexicon has an absolutely terrifying opening, if you happen to need glasses or contacts. One of the protagonists, Wil Parke, comes to with a needle in his eye. With no explanation by the men who are holding him captive, they force Wil to escape with them from an airport. People are trying to kill him and because Wil is suffering from amnesia, he has no idea who they are or why they want to kill him. Just as soon as Wil makes it to relative safety, Barry cuts over to his other protagonist and jumps in time to (I think) about ten years before Wil has a needle stuck in his eye. Barry introduces us to Emily Ruff, a young hustler who's been homeless for years. She's a master of short cons. Within pages, she is recruited to a very strange school that specializes in training poets. Of course they don't tell her this right away. Emily is left to piece together what they're trying to teach her with psychology, linguistics, rhetoric, political science, and a soupçon of mythology. She hones her already impressive skills in persuasion to the point where she can pretty much talk anyone into anything. What they don't teach Emily (or any of the other recruits) is ethics.
Barry switches back and forth between Wil and Emily, dropping hints as to why everyone seems to want to kill everyone else. Because I was reading an advanced reader copy, the section changes were abrupt or absent. All of a sudden the pronouns would change and I would have to reorient myself. I assume that this will be fixed in the final edition, otherwise a lot of readers are going to be lost. (It might not be entirely fair of me to judge the book on this basis, but I have to review the text I was given.)
With the changes in time and place, it's hard to get sucked into the narrative. Wil's plotline is tense like a thriller. Emily's timeline is a slow burn, more unsettling than captivating. The structure causes so many little cliffhangers that it's wearying. When the timelines finally get close to converging they get, if anything, harder to follow because there's even more jumping around in time. I have no problem with complex structures as long as they serve the narrative. However, I get the impression that Barry just couldn't think of a better way to lay out the story. Lexicon would have worked better, I think, if it had just one protagonist instead of two. On their own, the two plotlines are very interesting. They just don't work when they're smashed together.
The other issue I had with this book was the main villain. It doesn't take much effort to work out who's behind the schemes. At the end of the book, Barry explains why Yeats is the way he is, but that explanation turns him into a Big Bad because he doesn't know any other way to be. It also takes away any possibility of redemption. It cuts off the possibility of eleventh hour dramatic twists that I enjoy. In the end, the only option is to put him down like a sick dog.
There's a lot of potential in this book. Unfortunately, the problems with the structure and characterization made this book a chore for me to get through. If the final version of the book has the section breaks more clearly marked, I think this book will be a lot more enjoyable.