Ex-Marshal McCloud is now senator of New Mexico, fighting for a new environmental law. His enemy is Maitland, an unscrupulous owner of Chemtel, the world's most important chemical manufacturer. Shortly after McCloud gives an inspiring speech, he barely escapes a bomb explosion in his car and a shooting in a restaurant. When he learns that his niece, medical researcher for Chemtel, is killed, he begins to suspect that the attempts on his life were made by Maitland. He pays him a visit in Britain to make his own investigation.