This, the fourth book, in Salvatore's "Cleric's Quintet," is probably the worst novel in the five book series. There were a few promising ideas that could have been developed more but alas, no such luck. This book is meant to be the climax of the story, which resolves around the plans of Castle Trinity to conquer part of the Realms.
Cadderly, the lead character, becomes more and more powerful with each passing page. His development seems to have been arrested and I found him less interesting than in the previous books. In "Canticle" (which I've reviewed), Cadderly was inexperienced and he depended on his friends to help him. He also had several internal struggles that gave him some depth. However, here, Cadderly seems to be able to overcome any obstacle with little trouble.
The story development leaves something to be desired as well. Salvatore brings back one of the interesting villains from a previous book ("Nightmasks") and then dispatches him without so much as the villain facing off against Cadderly. Other reviewers have mentioned this and I have to find myself agreeing with them. Cadderly's incredible and frequent use of magic becomes something of deus ex machina. There are supposed to be limits on what magic (i.e. power) can accomplish and it seems something of the balance was lost here. It is a pitfall that every fantasy author must always attempt to steer clear off.
There is one development in this book that hints at what will happen to the Edificant Library (a bastion of priests and good gods) in the following novel. I don't want to say anymore on that note for fear of spoiling the plot.
Please refer to my review of all the other novels in this series.