Veronica Guerin, played by Cate Blanchett, goes to an Irish slum to see the drug addicts and how they live. Upset by what she saw, Veronica becomes interested in how the drug lords live the high life at the cost of the drug addicts becoming sick and dying.

Veronica meets John Traynor, aka "The Coach" played by Ciarin Hinds. She asks him questions about the drug trade and "The Coach" gives her answers, provided that the information she reports in the newspaper doesn't include him or his name.

The other side of Veronica is that she is a wife to her husband and a mother to her son. She lives a quiet life at home, however, her husband has worries and fears for her. Her mother, played by Brenda Fricker and her brother feels the same way; but they know that being a news journalist is a job Veronica enjoys doing.

A conspiracy ensues involving Eugene "Dutchie" Holland played by Joe Hanley. Veronica visits "Dutchie" earlier at his home asking him a lot of questions about the drug trade. Veronica meets "Dutchie" again at the airport. Dutchie tells Veronica as he was about to board a plane that since she visit his home, he should make a "visit" to her home.

That night, someone shoots a bullet through the window of her home. Not threatened in any way, Veronica discovers that the head of the drug ring is wealthy socialite named John Gilligan, played by Gerald McSorley. As she tries to get closer to him, an unfortunate incident occurs. Before she leaves her home to attend a Christmas party, a masked figure steps into her home and tries to kill her, but he only shoots her in the leg. This doesn't stop Veronica. She, now on crutches and limping around, still press the investigation of John Gilligan. She finally meets him at his home. However, John gives Veronica a horrible welcome by beating her up and throwing her into her car. She drives away from the estate bruised and shaken. Later, John calls Veronica and threaten to harm her son if she doesn't back off.