I actually read the bulk of this over a couple of days, after starting but needing to put it aside. Once I returned to the story, it was difficult to put down. Part of that was trying to untangle the threads of mysterious and confusing characters and plot that wanders between horror and action - this is not a complaint! I will admit that some of the lesser characters take some work to keep straight, but there is a glossary in the back [which I actually didn't even know about until I'd finished] and the longer you read, the more defined the supporting cast becomes. Gideon herself is an amazingly fun MC to follow; her snappy retorts and underlying kindness won me over. And her background story is... well, I don't want to spoiler but there's a lot to make you uncomfortable and sympathetic. Speaking of uncomfortable, I've seen mention from others about how some of the relationships in this book made them uncomfortable, and I agree but I think that's part of what makes the reveals at the end so impactful. The Ninth House is filled with secrets and those secrets exact a terrible price. I have a feeling that the next book in the series will be dealing more with exactly how dear the cost is, and I am looking forward to reading it.