Like the last two books in this series, Ward Against Disaster is a brilliantly written fast paced book. The characters are wonderful and the character arcs are progressing well We finally get an answer to Celia's condition in this book but it doesn't resolve much in the Ward/Celia relationship. Melanie Card writes extremely well and she manages to balance action and romance exceptionally well. She also writes Celia as a strong female character without turning her into a bitch or some totally damaged individual. (something that a lot of PNR authors have difficulty doing)
Ward is as usual the reason for this book's awesomeness. His desire to do the right thing, despite his capabilities is encouraging and his self will is impressive.
If Ward and Celia are incredible, the Nazarius is not a slouch either, from the threatening individual found in the first book, he's progressed into a strong, reliable friend. If I wasn't shipping Ward and Celia so hard, I certainly wouldn't mind Nazarius and Celia. The only issue I have with the book is the dragging out of the relationship and the keeping of secrets that should be better said, but this doesn't detract from the text.
I highly recommend this book as a worthy successor to Ward against Death and Ward against Darkness.