This is the third book in LaFevers' young adult series about budding Egyptologist Theodosia Throckmorton. Be sure to read the books in order of publication as the three stories lean heavily on each other making reading them out of order an impossibility.
That being said, I was a little put out by the extent that this book relied on the previous books in the series. Generally, I was able to recall the previous stories with LeFevers' reminders. But, at one point our heroine hears mention of a name and comments that she had heard this name discussed by another party in the book some weeks prior. Reading this on a Kindle, I was able to search the name, thinking I had missed some minor point earlier. There were three mentions of the name in the book and all three occurred within paragraphs of the first mention with nothing but a sparse reminder of who the person was. Fortunately, the name was only a background name and really didn't play at all into "Eyes of Horace". I still have no recall of this background character.
That aside, LeFevers does write a good YA story that has me wanting to continue on to book four in the series.