I'm afraid this wasn't a good book overall. I'm giving it 2,5 because there wasn't anything wrong with the writing, it's the pacing and narrative choices that were the problem. I believe this could have been much better with stronger editing.

The story is cool - two girls encounter spirits etc. -, but too little time was spent on the story. We have two POV characters: Treasure, whose narration is in the first person, and Ozoemena, whose story is told in the third person. I don't see the reason for this, especially since

Treasure dies at the end and is not the narrator for the whole story.

Ozoemena's story is mostly her daily life and her going to school. This was not interesting. Maybe if this was some kind of a coming-of-age story it would make sense, but the point is the interaction with the spirits. Also I don't really care for coming-of-age stories.

The characters were interesting, but their stories were just boring due to unnecessary and over-long scenes, especially in Ozoemena's parts, and she was in a bigger role than Treasure. I guess the author was trying to set the scene and the characters, but too much time was spent on, well, nothing.

Apart from these issues, the writing was good.

In short: interesting story, interesting concept, uninteresting execution.