The White Mountains

by John Christopher

Published 1 April 1967
Young Will Parker and his companions make a perilous journey toward an outpost of freedom where they hope to escape from the ruling Tripods, who capture mature human beings and make them docile, obedient servants.

The Pool of Fire

by John Christopher

Published 1 August 1968
Will and a small group of free people plan to destroy the three great cities of the Tripods before the arrival of a space ship destined to doom humanity.