The White Mountains: Tripods Series, Book 1

In the first book of John Christopher's classic series, it is the year 2100, and the world is controlled by the machines called Tripods. Life goes on largely as it had in the pre-industrial era, as all of humanity is subject to mental controls that prevent anyone from challenging the established order.

Will, a 13-year-old living in the small English village of Wherton, is looking forward to the transition to adulthood, which will take place on the next "Capping Day" - until a chance meeting with a mysterious Vagrant named Ozymandias sends him on a quest to discover a world beyond the Tripods' control.