The thriller, which plays out in real time, follows a single afternoon in the life of an elementary school teacher as she organizes a mixer of like-minded women. When the group heads home, the teacher encounters a woman from her past, leading to a volatile chain of events.
When Kath and her boyfriend arrive at a remote cabin in the redwoods, they find a mysterious younger couple already there. Her boyfriend disappears with the young woman, and Kath becomes obsessed with finding an explanation.