Frequency is a 2000 film, which contains elements of the time travel, thriller and alternate history film genres. It was directed by Gregory Hoblit and written by Toby Emmerich. The film stars Dennis Quaid and James Caviezel as father and son, Frank and John Sullivan respectively. It was filmed in Toronto and New York City. The film has similarities to the 1985 time travel film, Back to the Future, which shares several plot devices with Frequency. The film gained mostly favorable reviews following its release and was released in DVD format on March 1, 2001.

A rare atmospheric phenomenon allows a New York City firefighter to communicate with his son 30 years in the future via short-wave radio. The son uses this opportunity to warn the father of his impending death in a warehouse fire, and manages to save his life. However, what he does not realize is that changing history has triggered a new set of tragic events, including the murder of his mother. The two men must now work together, 30 years apart, to find the murderer before he strikes so that they can change history--again. Written by

John Sullivan (Caviezel) is a New York City homicide officer who is traumatized for 30 years following the death of his father, Frank (Quaid), After finding Frank's HAM radio, John begins talking to Frank, 30 years into the future. Together, they change the past but have to find a way to stop a serial killer from murdering John's Mom & Frank's wife with a 30 year gap. Written by Ryan Harder