Helen and Phil are a couple who recently fulfilled their lifelong dream of buying a house. One night, as they are driving home from a party, they have an accident. Phil, who is at the wheel, hits a person with the car on the unlit country road. Instead of stopping to see if the person is injured and needs help, he and Helen flee the scene.
The next morning, the doorbell rings. Outside stands Ina, who claims to have been hit by a car on the country road that night. Helen and Phil pretend not to know anything about it, but invite Ina into the house and offer her a cup of coffee. Ina then says goodbye, but soon returns and keeps coming back, each time under a different pretence.
First, she demands money as compensation for the accident, then the entire house. She even claims that it was her parents' house and that she has a right to it. While Ina appears to be the victim at first, it later turns out that she may have staged everything in order to get the house. As the play progresses, Phil finds a large stone in front of the front door and carries it into the house. Each of them will take this stone at some point, lift it up and consider whether to drop it on the other. In the end, Ina will ring the doorbell again, enter the house and sit down on the sofa next to Phil and Helen. The guilt that Phil and Helen have brought upon themselves can no longer be erased.