One cold morning in Victoria, Terry and Jeff arrive at the family home with a chilling plan to kill their stepfather, Rodger, who married into the family after the suicide of their biological father. Their motive is to force their dying Mum to change her will and testament, and to settle a score with Rodger for what they see as years of irresponsibility. The prospect of inheritance and retribution threads through the opening moments, setting a bleak tone for what follows.
Rodger is expected to return home at night to sell the family horse, and Jeff has drawn up a meticulous scheme to electrocute him by dropping a live radio into a bathtub filled with water. In anticipation of Rodger's arrival, Jeff compiles a to-do list: clean up the scene, manufacture an alibi of the brothers spending the weekend in Sydney, and rehearse the murder until every move feels almost inevitable. Terry, though scared, reluctantly follows the instructions, the weight of fear and doubt pressing on him as the plan tightens its grip.
As preparations unfold, the two brothers clash more than they cooperate. Terry begins to see the hollowness of the operation, while Jeff remains determined to press forward, his resolve hardening into stubborn insistence. The tension is undercut by a stark truth: Jeff is unemployed and may be plotting the murder as a way to secure the family home and stave off bankruptcy. Their escalating argument crackles with mistrust, until Rodger's early return interrupts the build-up and forces Terry to buy time with conversation.
Rodger reveals that the distance he kept from the boys during their childhood stemmed from Jeff's deep trauma after their father’s suicide, a revelation that adds moral complexity to the confrontation. He recalls the Sydney alibi and Jeff is compelled to reveal himself, tying Rodger up before dragging him toward the bathtub to carry out the murder. Terry, gripped by remorse, wrestles with the choice between stepping in and letting the plan unfold, but the moment passes as Jeff returns with the radio, and the grim work proceeds.
The sequence unfolds with a chilling efficiency: Rodger dies in the tub as the plan collapses into a grisly reality. The brothers set about cleaning the crime scene, only to be interrupted by the return of their mother, who has come home with Rodger after leaving him at the hospital. She grows impatient waiting in the car and enters the house, discovering Rodger's lifeless body and grieving over the loss. The shock ripples through the room as the core plan fractures under pressure.
A new, darker impulse emerges as Jeff suggests killing their mother as well, a notion Terry vehemently rejects. The tension erupts into a violent confrontation: the mother taunts Jeff with memories of their biological father, and Jeff fires the pistol, mortally wounding her. Terry bolts for the door, while Jeff retreats inside and locks himself in Rodger's car, only to be forced back out when Terry sets the petrol tank on fire. The struggle ends with Jeff taking his own life after a final, desperate attempt to reload the gun with bullets Terry has hidden and discarded earlier.
Amid the carnage, a different car arrives—the buyer for the horse—and Terry maintains faux calm as he engages her in conversation about the animal, seemingly oblivious to the horror behind him. The buyer senses something terrible but must press on, dialing the police once she realizes something is terribly wrong. Sirens begin to rise in the distance just as Terry returns with the horse, the scene freezing in a stark, distressing tableau. She asks what happened here, and Terry offers a quiet, unsettling line that lingers in the air: > "just some family stuff"
