Karen Rainey lives a sheltered life on the edge of the city. For the last five years, she has rarely left the home unless it was unavoidable. She has her food delivered to the front door. She works from home to avoid venturing outside and takes in the occasional housemate to aid her in paying the rent. But Karen isn’t agoraphobic. She’s terrified of her ex-boyfriend who is serving a life sentence in after Karen testified against him. With the constant threat that he might send someone to find and kill her, Karen keeps a low profile. But when a mysterious package is left on her doorstep, it sends Karen’s world into turmoil. Has her ex found her? Isolated and frightened, Karen befriends her current housemate, Beth. Trapped inside their home, Karen and Beth soon begin to lose their minds. But is the threat really outside, or is it closer to home?