Some qualifications. I am more a fan of heroic/sword & sorcery style fantasy. Robert E. Howard, Fritz Leiber, Michael Moorcock, C. L. Moore, JRR Tolkien, etc. Next, I did not realize until I finshed the book there is a prequel (Death of a Necromancer).
Ile-Rien is a land populated by wizards which is under attack by the Gardier, a mysterious enemy in dirigible like ships who use technology and magic together. Ile-Rien is slowly succumbing to the attacks, until the wizards realize they have a weapon to try against the Gardier. This mission to try the weapon against the Gardier is told from the viewpoint of a woman named Tremaine.
At 454 pages, this story plods along. There are a lot of descriptive passages throughout; while this can be seen as evidence that Wells has tried to create a convincing fantasy world, it gets in the way of telling the story and moving the plot along. I would argue, that Wells trips up in the creation of her fantasy world though when she mentions things like automobiles, coffee, and telephones.
The epsiodic nature of the book is vaguely reminiscent of the old pulps at times, with Tremaine and her friends going from "Burroughs-esque" adventure to adventure. The interspersed, detailed descriptions are what slow the story down though. (Yes, I don't need every single detail described--I have an imagination...)
The book also suffers from the plot being somewhat predictable. The only real surprise comes towards the end when the source of the Gardier's power is revealed--whether Wells develops this in the rest of the series remains to be seen.
From looking at the Amazon reviews, its clear this book will appear to some people. And that's great. If you like some of the writers I mentioned above though, I think you will find this book disappointing.