There is instant chemistry between Alice (Gillian Anderson), a businesswoman, and Adam (Danny Dyer), a younger working-class man who installs a security system in her London apartment. She takes him to a party in the country, and they end up making love. But the night turns horrific when they encounter three thugs who maim Adam and rape Alice. The incident turns them into fearful recluses until Alice spots the leader of their attackers (Anthony Calf) -- and the two victims plot a brutal revenge.
Casey is attacked at random on the street and enlists in a local dojo led by a charismatic and mysterious Sensei in an effort to learn how to defend himself. What he uncovers is a sinister world of fraternity, violence and hypermasculinity and a woman fighting for her place in it.