Frequency is a science fiction film released in 2000. It starred Dennis Quaid as Frank Sullivan and James Caviezel as John Sullivan, Frank's son. The film revolved around a CB radio which was able to transmit and receive radio waves between father and son during solar flares in the years 1969 and 1999.

Frank and Julie Sullivan were a happy couple living with 7 year old son John. Frank was a fireman, loving father and caring husband. He was a tough in appearance but loved his son and provided the best to him. He played baseball with him, taught him how to ride bikes and told him stories. Unfortunately the good life only lasted for a short time as Frank lost his life when fighting a fire in a factory.
30 years later, we saw that John has become a police officer but was still living in the same house. The son of Gordo, a neighbor who grew up a good friend with him, found an old radio in John's storeroom one night when solar flare was strong. While trying to fix the radio, John started chatting to a man with the same frequency and call sign as his. John talked with him casually at first and later found that the man at the other end called his son "little chief", the name his father Frank called him in his childhood. An initial mixed feeling of disbelief and emotion turned to panic as John frantically tried to warn Frank that the fire next day (30 years earlier) would take his life and "if only he chose the other way", he would be saved. Frank felt threatened that someone would know every detail of him and his son and left the conversation. The next day there was indeed a fire breaking out in the Buxton warehouse, the exact name of the factory John had warned him the previous night. Frank was anxious and confused during the course of rescuing victims from the factory. It transpired that there were indeed two exits - one covered with smoke and the other with fire. As a fireman, he instinctively felt he should escape through the smoke but suddenly remembered John's words. He decided to go through the exit that was covered with fire and found there was a slide out of the factory into the river outside, but had he chose the other way (with smoke) there would have been a big explosion killing both himself and the child. After Frank was saved from the river, he felt so happy and shouted loudly "little chief...."
The scene was so touching that I was emotional and believed I was not alone in shedding a tear. The story continued with John discovering that his father eventually died with lung cancer but he "saved his life" again by persuading him to quit smoking. However, the reality was suddenly changed (similar to Butterfly Effect) when John realized that his mother was murdered by a serial killer long ago. John had to compete with time to save his mother before the solar flare weakens. Can he do it? What will he encounter on the way? Enjoy this excellent film and you will see!