New York police detective Mark Dixon (Dana Andrews) is a guy who has to deal with his own demons on a daily basis at the same time as coping with the normal ups and downs of everyday life. The strain produced by his internal struggle and his intense hatred of criminals, leads him to make serious errors of judgement and to fail to recognise the need for any code of conduct to be adhered to in his dealings with people on the wrong side of the law. He has a track record of treating suspects and known criminals with gross brutality and this has brought him into conflict with his superior officers who have censured him for the amount of violence he has regularly used. Dixon cannot reconcile these calls for restraint with his own extreme and irrational hatred of all criminals. He is tormented by the fact that his father was a criminal and has been left with a powerful need to live down his father's reputation and to avoid fulfilling the low expectations that many people have of him as a consequence.

When a rich Texan is murdered following an evening's gambling run by gangster Tommy Scalise (Gary Merrill), Dixon is assigned to the case. Scalise tells Dixon's superior officer Detective Lieutenant Thomas (Karl Malden) that the victim had been accompanied by Ken Paine (Craig Stevens) and his wife Morgan (Gene Tierney) and that Paine had committed the murder. Dixon goes to Paine's apartment and questions the suspect who is both inebriated and uncooperative and when Paine punches him, Dixon retaliates and Paine collapses and dies. Dixon goes on to dispose of the body in a nearby river. Paine's wife is questioned and after describing what had happened at Scalise's place, adds that her father had gone to Paine's apartment later that night to take issue with him about the fact that she'd returned home with facial bruising. Paine had previously attacked her on a number of occasions and her father, Jiggs Taylor (Tom Tully), had threatened that if it happened again he would beat Paine up. This information leads to Taylor being arrested and charged with murder. Nobody accepts Dixon's explanation that Scalise had killed the Texan and then had Paine killed to eliminate him as a witness.

Dixon continues to make various attempts to get Scalise convicted but eventually realises that the only way to successfully achieve his goal is to write a confession about his own role in Paine's death and the cover up. He does this and also records that he is going alone to confront Scalise so that the police can arrest the gangster for Dixon's murder. The confrontation with Scalise and the eventual means by which Dixon achieves his own redemption, provide a tense and fitting conclusion to this gritty thriller.

Dana Andrews' strained and preoccupied expressions convey his character's perpetually troubled nature and his anxieties as he deals with a series of misfortunes which include and follow Paine's accidental death. Dixon, however, isn't the only one to experience misfortune as Morgan, a successful model loses her job because of all the trouble surrounding her. Her father, who'd some years earlier been awarded a diploma for assisting the police, unjustly finds himself charged with a crime he did not commit. Ken Paine who'd been a war hero had experienced unemployment and a loss of self esteem which led to alcoholism and wife beating and Scalise who'd been set up in business by Dixon's father also suffers his own misfortunes.

"Where The Sidewalk Ends" is a thoroughly engaging tale involving a group of interesting and diverse characters and a main protagonist who is the absolute personification of moral ambiguity.

Sentiment: positive