Rachel is a single mother navigating a tough morning; she's late for work and dealing with personal issues, all while trying to drop her son Kyle at school. Stuck in heavy traffic, she honks aggressively at another car that fails to move at a green light. The driver of the other car, a man named Tom, confronts her at the next stoplight, asking for an apology that Rachel denies. What seems like a minor incident quickly spirals out of control as Tom, who was already on edge from his troubled past, decides to teach Rachel a lesson for what he perceives as her lack of civility.

Rachel’s day turns into a living nightmare as Tom begins to stalk her, systematically ruining her life and threatening the safety of everyone she loves. His relentless pursuit forces Rachel into a perilous game of cat and mouse, revealing cracks in the seemingly mundane routines of modern life. The tension escalates with each encounter, pushing Rachel to her limits as she tries to find a way to protect herself and her family from Tom's unhinged rage.