This was probably my favorite book of the series, with a satisfactory ending. I love the writing style of these books, there a lightness to it that makes me smile all the time. This one has dirigibles, a boat trip, balloon trips, a cute metanatural baby (Prudence), children traveling with their parents, Egypt ancient mysteries, and adorable supernatural beings. (vampires and werewolves). It's witty, and sensible and classy. It was a true feel-good read. And I felt compelled to continue reading the next series (The Custard Protocol) that focuses on Prudence as an grown-up lady.