High ranking cleric Preston (Bale) is one of the best at what he does. He's efficient and merciless, even killing his own partner, Cleric Partridge (Sean Bean) when he discovers that he's begun feeling. Everything is in order, until Preston accidentally misses a single dose of Prozium. That one little mistake is like a drug, enough to bring all the thoughts, feelings and emotions rushing back little by little as he attempts to feel while hiding that he's feeling.
Preston also attempts to, and succeeds in, making contact with the Resistance; other men and women gone into hiding and trying to eliminate Prozium and its effects. In a dangerous gamble Preston offers up the Resistance to the Tetragrammaton for the chance to meet Father, the leader of the city of Libria. When plans go awry however, Preston has to use every scrap of training, along with every ounce of love, hate, rage and desire that he now feels to smash his way into the city's inner sanctum for a final battle that will decide the heart and soul of the people that he has sworn to protect with his very life.