Wow, wow, wow! There are vanishingly few authors that I would trust with a mystery box unreliable narrator setup like this, and Adrian Tchaikovsky is definitely one of them. When I consider series like this one, the first book is usually slightly ahead of the rest in terms of "which is my favorite", simply because it's the first one I fell in love with, but in this case, it truly would be hard for me to pick a favorite. It seems like this is the conclusion to the arc but I would drop everything if I heard he decided to return to this world. Absolutely stunning work, the number of times I yelled "what the *absolute* fuck is going on right now" with an unhinged delight grin on my face is uncountable. Time to go yell at everyone I know to go read this book.