This was an interesting take on how evil is spread in the world; that the Moon is the creator of all good things and that there are 13 witches who are her opposite, they sow chaos, death, and destruction; basically all bad comes from these 13 witches. One of the 13 has already been destroyed so there are 12 left at the beginning of the story, but nobody knows how that witch was destroyed. The story starts with The Memory Thief showing up at a hospital and taking a baby, a boy, from Annabelle Oaks, she also takes all of her memories. But, Rosie was a quiet baby and the witch didn't know about her so she wasn't taken and she survived. But Annabelle was a terrible mother and it's literally never explained how Rosie survived as an infant because Annabelle was barely able to function, so that part doesn't make a lot of sense. Anyway, fast forward 11 years. Rosie is now 11 and raising herself and making sure her mom is fine. She has a best friend, Germ, who is better than the boys at everything (Germ is a nickname, a mean girl called her that and she embraced it and it stuck). This book does a great job of addressing how kids change as they grow up and the insecurity they face, particularly when it comes to wondering if your best friend isn't going to be your best friend anymore because you start developing new interests and drifting apart. That stood out the most to me from this book. Yes, it was a fun fantasy adventure. Yes, Rosie was able to help one of the Ghosts' haunting her house finish his unfinished business and cross over to the Beyond, yes Rosie was able to figure out her witch weapon and defeat the Memory Thief thus returning her mom's (and everyone else's) memories, but the friendship and the way friendship changes as you change was really at the core of this story. This sets up beautifully for a second book. And truly, it sets up beautifully to be a long series; like 11 more books, one for each remaining witch. I very much enjoyed this and am looking forward to the next one.