The Pledge of the Sheriff
In the movie The Pledge (2001), directed by Sean Penn, a weary police chief, played by Jack Nicholson, investigates the murder of a young child. In the pivotal scene, on the day of his retirement, he promises the mother of the murdered girl to find the killer.
The sheriff gradually goes to extremes to fulfil his promise. He dedicates all his time to the case. He moves to a small town in the mountains, where he suspects the murderer could be found. The pledge he made propels him to forsake everything else. His mental health starts to decay. The guilt and shame of the unfulfilled promise lie heavily on his shoulders.
This movie reveals how incredibly powerful a promise can be, even today. Human beings can become very preoccupied in their quest to fulfil a promise.