This book started doing something which was a little unique for the series. The main book itself was an eductional account/field guide to the topic, however, supplementary material was added which told a story about a protagonist who recieved a copy of the said book in-universe. It makes the book twice as exiting as an interesting narrative is formed, tying into itself the information presented to us in the real book.
In this case the book itself is an illustrated guide through gods, heroes and monsters of Greek mythology, from the almighty Zeus to the creeping gorgons, with a plethora of fun retellings of famous myths with fun twists the series is known for. The side story recored on it's margins, however, is a cautionary tale of an archeologist who recieved a copy from the book's in-universe author, Lady Hestia Ewans, to serve as a field guide on his voyage through Greece collecting artifacts for a newly established archeological museum. He's driven mad with suspicion and indeed starts to believe in the stories of Greek mythology, ending in a tragic manner.
If you're fascinated by archeology, Greek history, culture and mythology, this book will certainly provide some neat insights into these topics. It's not a particularly detaild read, but as someone who reads everything and anything mythology related, I was ok with information provided, and even learned some new things upon first reading them. It reminded me quite a lot of Egyptology, with it's combination of supernatural, mythologycal and historical educational elements, tied together with a cohesive narrative story.