John and Jane Smith are a seemingly ordinary suburban couple who lead boring, uneventful lives working as construction and tech support, respectively. However, both are actually hiding a significant secret from each other – they are highly skilled assassins working for competing organizations. Despite their professions requiring them to live in the shadows, their marriage has grown stale over the years, and they find themselves in a rut, unaware of the true nature of each other's jobs. Their life together is a facade, built on little white lies and routine, as they try to maintain the appearance of a normal, loving relationship while hiding their deadly skills.

The couple's life takes an unexpected turn when they are both assigned to kill the same target. This mutual assignment reveals their true identities to each other and sets off a high-stakes game of cat and mouse. Suddenly, the very skills they have honed for their jobs are directed at each other, leading to a series of intense confrontations and a reexamination of their relationship. As they try to outwit and outmaneuver one another, they must also confront the reality of their marriage and whether their newfound knowledge of each other's secret lives has irrevocably changed how they see one another.