Michael Sullivan, a hitman for the Irish mob, leads a quiet life with his wife and two sons. His world falls apart when his wife and youngest son are killed by mobsters, prompting him to seek revenge.
Sullivan embarks on a violent journey with his surviving son, Michael Jr., who witnesses the brutal events. As they hunt down those responsible, Sullivan and his son grow closer, with Sullivan struggling to protect him from the dangers of his world.
Facing moral conflicts, Sullivan realizes the cost of his actions. He is forced to confront the fact that his violent lifestyle has put his son in harmβs way.
In the end, Sullivan avenges his family and confronts John Rooney, his former mentor. After the confrontation, he ensures his sonβs safety, choosing a path of redemption before meeting his tragic end.