The beginning was cliche and the characters were annoying, but I kept reading because it promised horror - and didn't fail. Every scene with Mary in it made my fists clench in fear. This wasn't the scariest book I've read, but it very definitely kept me on the edge. The ending felt very abrupt, though. 
 The characters: everything was so cliche and boring that I was annoyed at first. But as the ghost stalked them, I could finally understand them better. For this book, the beginning felt like it was filler, as if the chapters were written to just pass some time. Like to build up the tension, I guess? It didn't work though. It. Was. BORING. Reading the beginning didn't endear me to the characters much. Even though the author tried to make a background for Mary and how she became a villain, while I could understand it, it still fell flat for me. For me, the antagonist felt like it was someone else, partly because she pissed me off in the beginning; but she was a more subtle (*kind* of) villain. (If you read the book you know who I'm talking about, if you haven't, I don't want to bias you in case you choose to read the book) The writing wasn't perfect but for the most part of the story, I was so drawn in with the tenseness and the things that happened that I didn't notice it much and it didn't bother me. 
 The writing was okay, but it was the very tense, mostly creepy scenes that kept me reading.