My Goodreads posted:

I forget who originally recommended this book to me, but I remember their pitch was something like "It's a little like American Gods, but much more complex, and also queer". It's got a lot of American Gods in it, but also the Sumerian parts of Snow Crash and a vague postmodern sense of detachment from time and location. There's one(?) gay character, so there's that. Also there's a heavy coating of turn-of-the-millennium DeviantArt edginess. I'm not sure if this review will be spoilery, because honestly I couldn't tell you most of what goes on.

In terms of the plot, it felt inscrutable. There's this multiverse called the Vellum, and if you're one of the few who can sense it - supernatural beings known as unkin - you can travel and manipulate parts of it. There's also the titular Book Of All Hours, which is a map of the Vellum. There are two warring factions, loosely rendered as "angels" and "demons", but of course they're both evil and manipulative. It's 2017, and angels made nanomachines, and also not-Satan is a Middle Eastern dictator. But it's also social upheaval during and after the First World War, and also the antebellum American South, and also it's the late nineties. Sometimes it's a world similar to ours, occasionally it's vague steampunk or mythological Mesopotamia. Sometimes it's all of these on the same page.

The characters are equally inscrutable. For the most part they exist as unkin with a dozen incarnations across time and dimension, but it's never clear how connected all of these are. There's a young girl, named Phreedom, who as the only female protagonist is laden with all kinds of weird and awkward tropes of sexual assault and romance and motherhood. Also there's Thomas, the gay one, who disappears halfway through, and I thought he'd been killed off until he reappeared at the end. Most memorable is Seamus, who is written as the Ur-Irishman who's grouchy and broody and whose fookin' inner monologue is shot fookin' through with fookin' awkward Irish accent, to be sure.

This was a gruelling read. At first glance it's only five hundred pages, but the text on each page is so small and the perspective switches between character, time and place so often that it felt three times longer. Duncan uses four different fonts to complement the dozen different settings and plotlines, to the point where it reaches Illuminatus! Trilogy levels of density. But Illuminatus! was fun, and this simply isn't. There are great passages and some lovely ideas but they don't seem to go anywhere or mean anything beyond a shallow "makes you think, huh?". In a word, it was infuriating. There's a sequel, and I'm sure a lot of the seeds planted in this book will germinate and blossom in that, but I don't want to wade through another one of these. Maybe I'm being too harsh, maybe it's too soon after finishing it to write this, but I can't think of any other way to describe how relieved I am to be done with it.