If you watched the sequel, then you already know that it ended with the McManus brothers, played by Sean Patrick Flanery and Norman Reedus, in prison. The Boondock Saints 3: Legion will show that while in prison they’ve gained notoriety. He also explained that the story will give us some insight to the McManus brothers’ past and offer a flashback of the very first crime for the criminal killing duo.
The “Legion” part of the title refers to the legions of people who have taken the law into their own hands and become vigilantes just like the now infamous brothers.
Duffy went on to admit that he blames himself for the long delay between the second and third films, saying, “It’s my fault. It’s taken awhile… It’s cause I want to get it right.” I’m sure it will take even longer as there’s no shooting or release date in sight.