How does McTeague change over the course of the novel, McTeague: A Story of San Francisco?

McTeague undergoes a complete psychological metamorphosis in this book. In the beginning of the novel he is quiet, clumsy and submissive to a point. By the final chapter, he has maimed, stolen from, deserted and murdered his wife, skipped town and killed his former best friend, all in the name of power. His decline is at first barely perceptible, appearing only to be the natural process one goes through when a marriage leaves the honeymoon stage and enters into the rut of routine. Slowly, though, the reader is let into the psyche of McTeague, a place of unspeakable ugliness. At the end of the novel, when it becomes clear that Marcus really does get the better of McTeague, there reader is filled with a sense of justice, of having witnessed McTeague's getting his just desserts.