Synopsis: Controlled by their tireless electronic brains which were programmed to admit no possibility of defeat, the gigantic robot tanks known as Bolos were almost indestructible, and nearly unstoppable. Almost. Nearly. A sufficiently determined enemy armed with nearly limitless firepower and willing to sustain terrible losses could destroy a Bolo. But even a terminally damaged Bolo is still an opponent to reckon with. And as long as a Bolo's artificial intelligence retains a flicker of consciousness, its indomitable drive to defend the human race against all enemies will propel it forward. Bolos can be destroyed - but they never surrender! (adapted from the back cover text of the first edition)