Despite the catastrophic outcomes of her three previous house-sitting commissions, Thea Osborne is convinced nothing can go wrong on her next assignment. The Montgomerys have asked her to look after their house and elderly mother, Granny Gardner, while they take a holiday. The arrival of Jessica, Thea's daughter, is a welcome surprise, and while Granny's behavior is peculiar, so too are the Montgomerys' instructions to keep her trapped in the house. When a body is discovered next door it isn't long before Thea and Jessica find themselves involved and the quiet village turns out to have very sinister undertones.