A thoroughly enjoyable read. 

Two sisters, one afflicted by an apparent possession, one too young to truly understand what is happening, who is revisiting her memories of the incidents that made and ruined her childhood. 

The novel takes a fresh new approach to a ghost story, sprinkling in the unexplainable alongside rational explanations, rejection of the patriarchy, fear and access to information in the internet age, and a critical look at the exploitative nature of reality tv.

To me,

it is clear by the end that Marjorie wasn't possessed. To others, it may be clear she was.

This ambiguity in a "ghost-story" setting in this case works incredibly well. The reader may well make up their mind several different ways throughout the book before settling on what "really" happened. And I think that's the point. There is no objective reality in Merry's experience. She was too young, and her memories have since been forgotten, repressed, diluted, and altered by the media frenzy that she lived through, and has had to burden since.

Tremblay's writing is evocative, and kept me absolutely hooked.