This is the first book after "When the Tripods Came", and it takes place about 100 years after the invasion and takeover of earth by the Tripods. (This was actually the FIRST book Christopher wrote, it was published in 1967 whereas "When the Tripods Came" was published in 1988.) Will is a 13 year old boy living in an English village. He is looking forward to his transition to adulthood, which comes when every 14 year old is "capped" by the Tripods. This insures obedience and order, and keeps humans from rebelling. Will is not sure he really wants to be capped, and is suddenly given the opportunity to escape and travel to the White Mountains and live freely without mind-control with a group of other humans who have avoided being capped. This book is the story of his journey to the White Mountains (the Alps), specifically the Swiss Alps, with his cousin Henry and another young teen that they call Beanpole.