This is the third in this series I've read - I read #1 and #2 and then suddenly skipped to #16.
I do feel like Peters made a significant effort to make sure that the reader doesn't have to read all the previous entries, however, that made for a LOT of backstory-catching-up at the outset of the book. It was very slow to get started.
However, once it finally got moving, it was a fun, light adventure involving a journey to return to visit a lost tribe in the Egyptian desert. Plots, double-crossing rogues and colorful characters abound. It's sometimes a bit silly, but Peters' extensive knowledge of Egyptology really helps her create the atmosphere of 19th-century Egypt with both accuracy and an obvious affection.