At the beginning of the movie "Contact," a television signal from the 1930's is sent back to Earth almost sixty years later. Similarly, in "Frequency," a radio signal from the past (this time, from 1969) is received in 1999. However, in "Frequency," it is even possible to RESPOND!
The film begins in 1969, where we meet Frank Sullivan (Dennis Quaid), a fireman with a taste for danger. Indeed, in the film's opening scene, Frank goes into an underground tunnel to rescue some trapped workers, even though there is a live wire which can fall at any moment and kill (if not severely injure) anyone still in the tunnel. You see, Frank takes his job very seriously and will do whatever it takes to save lives, no matter how much he is putting his own life at risk.
Thirty years later, Frank's son, John Sullivan (Jim Caviezel), is a cop who loved his father but has been without him for most of his life; Frank, it turns out, died back in 1969 while performing a rescue. John still lives in the same house in which he grew up. While going through some old things in a closet, he happens upon his father's old radio; talking to people over the radio was Frank's great hobby. Even though few people, if any, still communicate this way in 1999 (since the advent of Internet chat rooms has made it unnecessary to communicate with others by radio), John decides to try out the old machine.
Lo and behold, he reaches someone. It turns out that this someone is none other than Frank Sullivan, thirty years in the past! This is because an unusual cosmic phenomenon that lasts for six days and comes around every thirty years is occurring both in 1969 and in 1999; somehow, this phenomenon is enabling Frank and John to talk with one another across the expanse of time.
John is the first to realize what is happening. Frank, naturally, is a bit skeptical, but any doubts he may have are quickly dispelled when John accurately "predicts" the outcome of a baseball game. Through the radio, John is able to save his father from dying in the fire: the first time around, Frank had made the mistake of "following his instincts" in escaping from a burning warehouse; armed with John's warning, Frank does not make this same mistake "again."
History is thus changed. However, John is the only one in 1999 who remembers both versions of history - everyone else only remembers the "new" history. But by changing history for the better, John has also made things somewhat worse: a murderer in 1969 who was never caught had only killed three people in the old history; in the new history, he kills ten people. Worse yet, one of his "new" victims is John's mother! John the policeman in 1999 and Frank the fireman in 1969 must thus work together to solve this thirty-year-old case before it's too late.
The science of the movie seemed a little bit off: even if you could talk to somebody thirty years in the past, I highly doubt you could change history by doing so. After all, anything you say to the person in the past you already said, and any action that the person in the past takes in reliance on what you tell him has already occurred. Thus, it seems unlikely that you could change history by telling the people in the past how to remedy their mistakes, because if they remedy their mistakes, then it has already occurred, but if it has already occurred, then there would be no mistakes to remedy, and, well, you get the picture.
Nonetheless, if we leave the science aside and just accept the movie on its own terms, we are left with a moving story about talking to loved ones who passed away long ago. Watching this movie, I thought of my grandparents, who died over twenty years ago. I miss them very much and would give anything to be able to have just one more conversation with them, if for no other reason than simply to let them know just how much I love them. This movie, then, is really about that desire we all have to be able to talk to loved ones we have lost, just one more time.