This is the third instalment in The Great Library series from author Rachel Caine. Book 1 is called 'Ink and Bone' and Book 2 is 'Paper and Fire'.
Rachel Caine has created a creative parallel world where the great library of Alexandria not only still exists but has an enormous amount of control over the world. The characters in this series are enjoyable to read about and the storyline keeps you captivated.
In this book Jess Brightwell and his friends are on the run from the library and they have the knowledge to remove the iron hold the library has over the world, but to get that knowledge out there they have to contend against not only the library but the burners and the smugglers also (who always have a price). A beautifully creative world filled with interesting characters and a captivating story line.