The Kingsman secret service tries to stop the billionaire genius Richard Valentine from carrying out a mass genocide to reduce the world's population. Harry Hart recruits a troubled young man named Eggsy and trains him to become a Kingsman, despite Eggsy initially failing the final test. After Harry is killed, Eggsy continues the mission to stop Valentine. They discover the head of Kingsman, Arthur, has betrayed them and joined Valentine. Only a few Kingsman remain to stop Valentine's plan on their own.