Yawn. Boring. Besides one scene in the real world, no plot actually progresses in this book. They weren't at Egypt when they started this book and they still aren't at Egypt when they finish. In the meantime they meet some people who all die, and waste some time dicking around with a "We're Americans rah rah!" speech that is clearly a plot hole in the service of needing ACTION TO HAPPEN.
You can comfortably skip this one without missing anything in the series.