Impulse (1984) Plot Summary Explained

A minor earthquake triggers the outbreak by rupturing a hidden toxic waste vault that contaminates the local milk supply. Residents who consume the milk, most notably Stuart, experience a release of suppressed impulses, leading to violent and self-destructive behavior. The contamination acts as a chemical catalyst that removes social inhibitions.

Foreshadowing: Early scenes show Stuart drinking the local milk while Jennifer abstains, establishing the contamination vector.

• toxic waste
• milk contamination
• earthquake
• behavior change
• impulse

Jennifer never drinks the contaminated local milk, which is the vector for the strange behavior affecting the townspeople. She only accepts water and avoids the dairy product throughout her stay, making her the only uninfected person able to escape. This contrast is established early when Stuart drinks the milk while Jennifer declines.

Foreshadowing: During the arrival scene, Jennifer explicitly refuses the local milk that Stuart consumes.

• jennifer
• immune
• contamination
• milk
• survivor

The children have consumed the contaminated milk just like the adult residents, triggering violent and aggressive impulses. Jimmy brutally breaks his own arm and, along with Shawn, systematically tries to prevent Jennifer from leaving, slashing her tires and trapping her in the garage to set it on fire. Their behavior mirrors the town's overall descent into lawlessness.

Foreshadowing: Jennifer discovers Jimmy has already seriously injured his own arm before the attacks begin.

• jimmy
• shawn
• children
• violent attack
• garage fire

Dr. Carr, the town's physician, succumbs to the same contamination effects as other residents, losing his moral inhibitions. He euthanizes Margaret (Jennifer's hospitalized mother) and then commits suicide, demonstrating how the contamination destroys even trusted authority figures. This collapse of medical authority leaves the town without help.

Foreshadowing: The increasing odd behavior among all townspeople sets up the breakdown of societal structures.

• dr carr
• margaret
• euthanasia
• suicide
• physician

Stuart discovers in the woods a recently repaired toxic waste vault that has leaked into the milk supply. He traces the contamination conduit directly to the dairy facility, revealing that the outbreak stems from deliberate environmental negligence rather than natural causes. This discovery provides the concrete cause behind the town's mysterious behavior change.

Foreshadowing: The milk is established as a focal point from early in the film, with Stuart consuming it while Jennifer refuses.

• toxic waste
• vault
• milk facility
• contamination
• leak

Two men load a biplane with barrels of liquid at an airfield and take off to spray the substance over the town. A nearby government vehicle filled with radios reveals plans for coordinated spraying. This confirms the contamination was not accidental, authorities knew about the toxic leak and attempted to cover it up by dispersing the substance, likely to eliminate evidence.

Foreshadowing: The toxic waste discovery foreshadows a larger conspiracy behind the contamination.

• government
• biplane
• spray
• conspiracy
• cover-up

Stuart confronts a man at a government vehicle whose radios reveal the spraying plan. The man shoots Stuart with a shotgun when he approaches, silencing his attempt to uncover the truth. Stuart is killed for getting too close to discovering the conspiracy behind the contamination and planned cover-up.

Foreshadowing: Stuart's discovery of the toxic waste vault leads him directly to investigate the source.

• stuart
• shot
• government
• confrontation
• death

Jennifer witnesses the man shoot Stuart and, in a desperate act of self-preservation, drives her pickup directly at him, running him down and killing him. This moment marks her transition from witness to active participant in the violence, forced to take extreme action to survive. It underscores the total collapse of safety and law in the town.

Foreshadowing: The earlier garage fire attack already pushed Jennifer toward desperate survival measures.

• jennifer
• kill
• retaliation
• self-defense
• stuart death

Stuart discovers that Jennifer's brother Eddie harbors incestuous feelings for her, a result of the contamination removing his moral restraints. When Stuart confronts Eddie about this, the situation escalates and Stuart kills Eddie. This adds a deeply disturbing personal tragedy to the escalating chaos, demonstrating how the town's corruption reaches into the protagonists' own family.

Foreshadowing: The general breakdown of moral inhibitions among townspeople foreshadows extreme revelations.

• eddie
• jennifer
• incest
• stuart kills

The town descends into mass death, with roads and streets littered with corpses from the violent outbreak. A news report confirms that government agencies have no explanation for the mass casualties. Jennifer becomes the sole survivor, walking away from the devastation as the sun sets, leaving behind a town destroyed by both the contamination and the attempted cover-up.

Foreshadowing: The steady escalation from odd behavior to violence foreshadows total societal collapse.

• mass death
• corpses
• town destroyed
• survivor
• ending