One of my favorite characters in this book is Mark Studdock. He is what I would call the "redemption character" of this story (other characters that I would place in this category are Edmund Pevensie and Severus Snape - I think the redemption character is always the best one). For most of the story, Mark is completely taken in by the wrong side. Finally, he comes to the point where he sees the vanity and folly of everything he has been pursuing, and at that moment he comes to the beginning of his own realization of the inevitable truth.
"Whether because he had already survived an attack, or because the imminence of death had drawn the tooth of his lifelong desire for the esoteric, or because he had (in a fashion) called very urgently for help, the built and painted perversity of this room had the effect of making him aware, as he had never been aware before, of this room's opposite. As the desert first teaches men to love water, or as absence first reveals affection, there rose up against this background of the sour and the crooked some kind of vision of the sweet and straight. Something else - something he vaguely called the "Normal" - apparently existed. He had never thought about it before. But there it was - solid, massive, with a shape of its own, almost like something you could touch, or eat, or fall in love with.... He was not thinking in moral terms at all; or else (what is much the same thing) he was having his first deeply moral experience. He was choosing a side: the Normal.... The vehemence of his choice almost took his breath away; he had not had such a sensation before."
If you haven't read the Space Trilogy, go read it.