i first read this way back in the 70's and, to be honest, i scared me witless for years after. maybe i was a sensitive child or something. so i came back to it a cynical adult and after the first twenty pages i was laughing at my previous fears, but then the plot really kicks in and remarkably for a thirty year old kids book it hasn't dated. without including spoilers take liberal doses of paranoia from 'the matrix' and 'the truman show'. Throw in the blitz and season with a random futuristic utopian city run by old people and boil for an afternoon. so, if you want your kids to grow up with a healthy questioning mind, get this book. if you felt like me about it, buy this book and if you've stumbled in here in error, buy this book. seminal.