Sacha Baron Cohen stars as Norman 'Nobby' Butcher, a who lives in Grimsby with his lusty wife Dawn (Wilson) and eleven hooligan children (two who are his grandchildren) in the working-class town of the film's title. Despite the large family, deadbeat welfare-scammer Nobby still yearns for one more person in his life, his younger brother Sebastian, who he was separated from as a young boy when they were left as orphans and adopted into different circumstances. After learning of the whereabouts of Sebastian, who is now a slick and debonair secret agent working for MI6, Nobby meets and tries to reassert long-dormant bonds, but Sebastian wants none of it at this point in his life, having felt abandoned way back when. During a particularly tense moment at a public function that draws out Sebastian into full super-spy mode to avert an assassination, Nobby ends up bungling the heroics and makes Sebastian look like the culprit, causing the latter to have to hide out from his own spy organization. Sebastian tries to regain separation, but Nobby is all he has in this world to help him, especially as he learns of nefarious plans being hatched from an international terrorist organization that could put the world in mortal peril.