Gary “Eggsy” Unwin (Taron Egerton), whose late father secretly worked for a spy organization, lives in a South London housing estate and seems headed for a life behind bars. However, dapper agent Harry Hart (Colin Firth) recognizes potential in the youth and recruits him to be a trainee in the secret service. Meanwhile, villainous Richmond Valentine (Samuel L. Jackson) launches a diabolical plan to solve the problem of climate change via a worldwide killing spree.