The book opens up with Jess and his group having been betrayed by the leader of the Burners in America, after his father struck an unholy deal with them. The lot of them were translated to Philadelphia, the American Burner stronghold that has been under siege by the Library's forces for over a year, where they are being held in the hopes that they will be of some use to the Burners' leader, Willinger Beck. What Beck has yet to learn is that Thomas and Jess have Thomas' plans for making a printing press and can provide this crucial knowledge to the Burners, thus negating their need to burn books to make a point. Why burn a book when you can distribute them freely to break the Library's hold on knowledge? This, of course, is the goal of Wolfe, Brightwell and the rest as well, and if it takes pretending to work with the Burners to survive and carry on the fight, then so be it. Little do the Burners know that Thomas and Jess are building far more than just a printing press to aid in their escape from Philadelphia. And escape it they must, especially when some of their own are injured in a damaging attack on the prison where they are being held.
It is here that the group is introduced to the local doctor, a Native American named Askuwheteau who, while not too happy about treating the Library folk, at least seems to hold books in a much higher regard in general than the other Philadelphians. After observing Morgan, he has some choice advice for Jess, especially as it pertains to Morgan using her powers, which are growing greater with practice.
Their overall escape plan and printing press scheme is interrupted by a savage Greek fire attack on Philadelphia by the Library's High Garda, and the core group, along with the entire Philadelphia community, will find themselves fighting for their very lives. But as it always is with this bunch, they soon find themselves out of the frying pan and into the fire... Fortunately, Jess and Santi still have a few allies remaining and they'll have to rely on the good will of family and friends to extract themselves from the pickle they now find themselves in. But who can they truly trust, if anyone?
As I was reading Ash and Quill, I found myself flipping to the last page to make sure there was another installment, simply because these books are so good, I didn't want the series to end. Thankfully, there is another book lined up, which is good because it feels like there is so much more story to tell for these adventurers. I can't recommend this series any more highly. For fans of fantasy, science, and adventure, it just doesn't get any better than Rachel Caine's The Great Library series.