Wesley Gibson (James McAvoy) is a cube-dwelling hypochondriac, with a boss who humiliates him and a cheating girlfriend. His life is going nowhere.

Wes discovers that his estranged father has been brutally murdered and finds himself thrust into a secret society of assassins, called The Fraternity. During his training, at the hands of a skilled mentor named Fox (Angelina Jolie), this once office-bound wimp develops lightning-fast reflexes and superhuman dexterity.

However, with his first assignment, Wes finds out that the only thing more difficult than ending the lives of others, is summoning the courage to take control of his own.