I'm a firm believer that kids need creepy. There's a reason Goosebumps and Scary Stories to Tell in the Dark have persevered over time, and Serafina and the Black Cloak tries pretty hard to be in that same vein, but ends up wildly missing the mark.
Serafina is a girl who was found in the woods, battered and broken. Taken in by a man and kept secret for the first decade or so of her life, she is witness to a strange disappearance that she feels uniquely qualified to get to the bottom of, and so begins our tale of Serafina exploring and uncovering a dark, weird secret.
The first bit of the book, the parts that establish who Serafina is and what she's really up to? Pretty great. The moment we get to the meat of the plot, however, the story screeches almost to a halt, with a few interesting scenes scattered amongst a tale that plods toward a conclusion - a conclusion, by the way, that is a very pat, firm, almost Disney-style ending that nearly betrays the entire tale. It's a frustrating read because all the parts are there for a truly great read with some really interesting elements, but basically only a third of the story is really truly worth the time or effort, leading to a supremely disappointing story.
Of course, as is typical, I appear to be in the stark minority on this. People seem to overwhelmingly love this book, from the setting to the characters to the tale itself. As for me, while Serafina is an engaging enough heroine, she deserves a much better story than this, and middle grade readers who are looking for a creepy story to keep them up at nights deserve something that's much more substantial. I don't know if I missed something significant here or what, but this didn't do it for me at all.