edge of darkness is a 2010 british-american conspiracy political thriller film directed by martin campbell, written by william monahan and andrew bovell, and starring mel gibson. it was based on the 1985 bbc television series of the same name, which was likewise directed by campbell. this was gibson's first screen lead since "signs" (2002), and follows a detective investigating the murder of his activist daughter, while uncovering political conspiracies and cover-ups in the process.