A little frustrating

It took me at least reach a third of the book to really dive into the novel.
Early impossible to know if one is in lantiquité or in the future, what are the characters lon follows The author propels us into his world without give us the keys which makes reading difficult, and even more when the sinterrompt reading. For my part I havent found the glossary at the end of book quaprès finishing the novel. A prologue would have been welcome!
Descriptions (too?) And detailed a few lengths further add complexity to understanding.
The story is interesting, more science fiction with a dose of "metaphysics" that bit of bed. The characters are compelling. But the above difficulties understanding spoil history and leave a feeling of frustration.