In this chapter the reader is introduced to the Instant Aggression Model that underpins the rest of the book. Unlike other models of aggression IAM is specifically designed to provide the helping professional with a map to guide them through dangerous encounters as they happen, second by second. Three types of aggression are identified, each driven by a different force - an unpleasant emotion, a cognitive or perceptual disturbance, or a goal. Furthermore each of these forms of aggression can be either Difficult or Dangerous and the point at which one transforms in to the other is known as a Pivotal Point which differs in nature according to the form of aggression encountered. It is proposed that through an understanding of rapid cognition it is possible for the helping professional to know what they are dealing with in an instant and then, with training, engage immediately in safe and appropriate "front-end" skills.