When the alien Tripod machines land on Earth, they don't seem much of a threat. The first skirmishes end in victory for the human forces. But the real danger - the insidious mind-controlling powers of the Tripod Masters - is only just beginning. Laurie and his family must flee their homes as the invaders tighten their tentacled grip - and find a place to start the fight back... The thrilling and eerie prequel John Christopher's classic dystopian Tripods series is available for the first time in ebook format.