A young couple, Gemma and Tom, search for their first home together and are directed by an odd real estate agent to a suburban development called Yonder. Upon arrival, they find themselves in a bizarre, identically designed neighborhood that feels unsettlingly artificial. After exploring an identical house, they attempt to leave but discover that all roads lead them back to the same house, number 9. They are inexplicably trapped with no way out and no sign of any other residents.

As days pass, their situation becomes increasingly dire. They receive mysterious supplies and eventually find a box containing a baby, along with a note instructing them to raise the child in order to be released. The child grows at an alarmingly fast rate, exhibiting strange and eerie behaviors. Gemma and Tom's relationship deteriorates under the stress, and they struggle with the oppressive environment and their inexplicable situation. The oppressive control of their unseen captors continues to deepen the couple's despair as they grapple with their surreal predicament.