Psychologists John Lockwood and Marion Lawson run a sex offender treatment group at the state prison at Santa Fe. They agree on two things, and not much more. One is that treatment helps some (but not all) offenders, and the second is that Leon Darwin is one that isn’t really going to benefit. Darwin is a sadistic rapist, a sociopath who goes to their treatment group because it is required for parole, but he doesn’t want to change. He wants to get out and not get caught the next time.Lockwood has seen a few sociopaths in his years as a prison psychologist. They often end up in prison, though only a small proportion of inmates meet the full criteria. Some do, and they are terrifying. Darwin does every day of a ten-year sentence and build a reservoir of rage and hate, and determination to have his revenge. Now he’s out and young women are disappearing across southern New Mexico