Promise, Oklahoma is in the middle of the south central US, more commonly known as Tornado Alley. A deadly twister has left people dead and injured and caused 40 million dollars worth of damage. At first it seems as though the Pepper family are just four more statistics on the death roll, but Police Chief Charlie Grover soon realises that their bodies have been arranged to look like storm victims, while the cause of their deaths is by the hand of man, not an act of god. The post mortems confirm his suspicions, then another death during a tornado proves that there is a killer at large. He seeks help from meteorological experts at the local university, in particular Dr Willa Bellman, who knows all about the force and power of these storms and also knows the motley collection of people who follow the paths of every tornado. Both of them are convinced that amongst the storm-chasers is the killer, but more deaths - both natural and unnatural - are to occur before the killer is stopped in a truly breath-taking climax.