Evie O'Neill has been exiled from her boring hometown and shipped off to the busy streets of New York, and she couldn't be more thrilled. New York is the city of speakeasies, shopping, and movie palaces. Soon enough, she's rubbing elbows with Ziegfield girls and rakish pickpockets. The only catch is Evie has to live with her uncle, the curator of the Museum of American Folklore, otherwise known as the Museum of the Creepy Crawlies. When a rash of occult-based murders starts up, Evie and her uncle are right in the thick of things, and through it all, Evie displays a mysterious ability, one that could help catch the killer... if he doesn't catch her first.The Diviners is like an epic mystery highlighting an important and wondrous period in New York's rich history. Copious amounts of glitter, glamour, and 1920's female sass fill the pages and mix together with a supernatural murder mystery that spans decades to create something huge. And it is huge, judging by its page length. The length provides extensive detail, backstory, and mystery for the reader, but the reader will have to stick with it, stick with the snippits of secrets and the shifts between different main and supporting characters to reach the end.A compliment I can give to Libba Bray is that the entire book, not just certain characters or locations or events, read like it came out of New York in the 1920's. The voices of the characters and the tone of the book both sound so authentic, down to the little mannerisms and the slang words. And there are lots of characters with their own little authentic mannerisms. The summary is a little misleading, the book isn't all about Evie and her experience with the mysterious killings, but it possible that it comes with the third person point of view and the length of the book, objectively being shown multiple sides of the story but not revealing everything. It moves moment by moment, only showing the readers as much as they need until the end.I was surprised at how dark and dangerous the paranormal side turned out to be, how evil the shadows could be. Taking Evie and her happy-go-lucky life's a party attitude into account, the book was far darker than I expected. It was an exciting surprise for me, but I'm not sure how other readers will feel.Evie and her adventures do take up a fair amount of the book, but there's also Memphis and his less than legal dealings and his less than happy home life. Then there's the greater side characters, Evie's friends and her uncle. Then there's the dark shadowed side committing gruesome murders. Then there's the lesser side characters, the few who appear only half a dozen times who have their moments which either continue the story, filling a small gap, or set up a slew of questions that might be answered in a future book.The length of the book and the weaving in of the paranormal and the intrigue make me curious about the author's outlining process. It's such a complicated and heavily-plotted out book, I can only imagine the amount of outlining and world-building, the background research that had to be looked up. There are hints of connections with everything and everyone. Evie, Sam, Theta, Memphis, Jericho. Almost everyone that's mentioned has a connection to someone else, to the murders, to what's happened and what's to come.Enough was given and and enough was held back to set up what's to come in the series, but there's a lot to remember. So many characters are important, main and side characters, and they all have secrets of their own so there's no way of knowing which will shape the rest of the series and which won't. Before the next book comes out, a re-read of this first book might be in order.