A fleet of Martian spacecraft surrounds the world's major cities and all of humanity waits to see if the extraterrestrial visitors have, as they claim, "come in peace." U.S. President James Dale receives assurance from science professor Donald Kessler that the Martians' mission is a friendly one. But when a peaceful exchange ends in the total annihilation of the U.S. Congress, military men call for a full-scale nuclear retaliation.

Once an architect, Frank Bannister now passes himself off as an exorcist of evil spirits. To bolster his facade, he claims his "special" gift is the result of a car accident that killed his wife. But what he does not count on is more people dying in the small town where he lives. As he tries to piece together the supernatural mystery of these killings, he falls in love with the wife of one of the victims and deals with a crazy FBI agent.