Homebound

Olive has been kept in his house for months, not allowed to go outside. They lived in a city, but had a large, open-spaced house with plently of places to run, but that wasn't the problem. As a pup he was allowed to prance around their backyard all he liked, and he often pushed under the fence to meet with his one friend, Jess. She would remind him each night, that something terrible was gonna happen, but Olive ignored this, thinking nothing could happen. Then he witnessed something horrible; he watched as Jess got dragged away with a steel rope around her neck. Since then, his owners never let him out. Why did his owners keep him in their house, why cant Olive forget her, and what did Jess know?