The City of Gold and Lead: Tripods Series, Book 2 (Unabridged‪)‬

In the second book of John Christopher's classic series, Will Parker and his cohorts have spent a year living among the free men in the White Mountains. The Resistance charges them, now wearing realistic yet harmless caps, to infiltrate a Tripod city by competing in a sporting exhibition called "the Games" (very similar in nature to the Summer Olympics), in which the winners of the events are to be offered to the Tripods for service.