Bullhead

Twenty years ago, Jacky and Diederik were childhood friends. Jacky's father, a cattle farmer, had mafia connections and drew the boys into risky deals. The seeds of their later conflict were planted early.

During a family outing, Bruno attacks Jacky and castrates him with rocks after catching him trying to visit Lucia. The attack scars Jacky and drives a wedge between the two boys, while Diederik leaves. Diederik's father later forbids him from talking to the police to protect mafia ties.

To compensate for his injuries, Jacky begins injecting testosterone as he goes through puberty. The loss shapes his aggression and ties him more closely to the underworld.

In Sint-Truiden, Jacky visits a distant relative and intimidates him into selling cows to the mafia. The exchange shows his growing power over ordinary farmers. The relative agrees, fearing repercussions.

In the Limburg province, a mafia cartel dominates the cattle and meat trade using illegal growth hormones. Farmers sell cows to the mafia, who inject them before slaughter. This system ties animal farming to criminal profits and public health concerns.

A West Flanders mafia thug returns a car to two Walloon mechanics, telling them to disappear. They discover a bullet hole and a news report about a murdered detective, realizing the car is connected to a bigger crime.

Jacky's veterinarian arranges a deal with Marc, the West Flanders mafia boss. At the meeting, Jacky is introduced to Marc's associate Diederik, who is secretly a police informant.

Diederik operates as a police informant and is employed by Detective Eva, who is investigating the hormone mafia. The past and present collide as old friendships return to haunt them.

Jacky sees Lucia in a store and begins following her, driven by a fixation that straddles affection and danger. His obsession grows as he trails her through the evening.

Later, at a nightclub, Jacky follows Lucia and savagely attacks a man who flirts with her. The violence exposes the depth of his rage and his mounting isolation.

Lucia visits Bruno, who is disabled and mute in a care home, and begins to suspect that Jacky was involved in the earlier attack on her friend. The past resurfaces to complicate their relationship.

The police locate the stolen car and arrest the mechanics, suspecting Jacky of involvement in the detective's murder. Diederik rushes to warn Jacky that the police are closing in, and they decide to flee together.

Jacky tries to see Lucia again, but she refuses entry at first; she invites him in and reveals she had called the police, knowing he attacked her friend. The tension intensifies as truth and danger collide.

In Lucia's bathroom, Jacky injects a high dose of testosterone. When the police arrive, he attacks the officers in a rage and is fatally shot in the stomach.