The Edge of Darkness is based on a six-hour BBC mini-series in 1985. Boston Police homicide detective Thomas Craven (Mel Gibson Mel Gibson), a single father who loves his 24-year-old daughter, is killed on his doorstep one day. Thomas thought that the real target of the killer was himself, and stubbornly he plunged into the case, but with the deepening of the investigation, he found that there was something else about his daughter's murder, and behind the case was the corruption of the entire government system.