Because of an unusual amount of sun spot activity, amateur radio operator (and professional firefighter) Frank Sullivan (Dennis Quaid) is hoping for a long distance conversation one evening in October of 1969. He is disappointed when the only signal he picks up belongs to a policeman named John (Jim Caviezel), who is a fellow resident of Queens NY.
It isn't until their conversation turns to baseball, that both men become suspicious. John is able to tell Frank the upcoming plays of the 1969 World Series as if they had already happened. A few more probing questions reveal that through some incredible coincidence of atmospheric physics, these "neighbors" are actually separated by time, not space, and that John is Frank's son -- thirty years in the future.
John is perhaps the most surprised because Frank is deceased. When he overcomes the initial amazement, he realizes his father is living one day prior to the fire that claimed his life. Convincing him to make a different decision that will allow him to live, John and Frank begin to set a complex chain of events into motion that will make them acutely aware of how even small choices can have a major impact decades later.
Dealing with the consequences of altering the past, isn't a new premise, though using a radio to speak across time is an interesting twist. Certainly for anyone who wishes they could have one last conversation with a loved one, Frequency will strike some sensitive notes.
But the warmth of this family feeling is lost when John realizes that saving his father's life has cost him his mother's. At that point the story becomes just a murder mystery with a science fiction bend. As John delves into the investigation of a serial killer, the audience becomes witness to police pictures of sexually assaulted and murdered women. Both father and son are involved in acts of violence because they are desperately trying to stop the murder. These scenes will likely disqualify many families from tuning into Frequency.