Susan is a young mother who lives alone with her husband and child. After her husband is called to go on a business trip, she is left to fend her postpartum depression by herself. Eventually, she reaches her breaking point. Her baby won't stop crying so she decides to silence it.
The next day a salesman named Eustace shows up at Susan's front door, he steps into her home to pitch his product. Once inside he visits the bathroom where he finds blood in the sink. On his way back to the living room he finds the child's room, whereupon looking inside he uncovers Susan's secret. While attempting to contact the police he is killed by Susan, who then takes his car keys and flees the scene.