While hunting down the killer of a fellow policeman, veteran detective Jim Wilson grows increasingly morose and violent, causing his more even-tempered partners, Bill "Pop" Daly and Pete Santos, concern. Acting on a tip from a news vendor, Jim goes to see Myrna Bowers, whose boyfriend, Bernie Tucker, is rumored to be a cohort of the suspected murderers. Jim convinces the battered Myrna to reveal Bernie's whereabouts, and after he tracks Bernie down, beats him into betraying his partners. Although Jim's actions lead to the arrest of the killers, his superior, Capt. Brawley, informs him that Bernie's lawyer is threatening a brutality lawsuit and cautions him to take it easy. Later, however, while on patrol, the detectives hear a woman scream and discover Myrna being beaten by two thugs. Jim grabs one of the men and, without thinking, starts to rough him up. After interceding, Pop, a father of seven, angrily advises Jim to stop wallowing in the job. The next day, Brawley yells at Jim that he is becoming a liability to the department and assigns him to assist in the investigation of a young woman's murder in the rural north. Jim drives to the snowy mountain town of Westham, where Sheriff Carrey fills him in on the case. Carrey and Jim then go to the victim's home and talk briefly with her sister, Julie Brent, who witnessed the crime. Just then, the victim's brother rushes in to announce that the killer, a stranger, has been spotted running across a nearby field. Along with Julie's revenge-hungry father Walter, Carrey and Jim chase after the fugitive, but he hijacks a car before they catch up to him. Walter and Jim pursue in another car, but blinded by drifting snowfall, end up crashing into the killer's abandoned vehicle. The murderer's snowy footprints lead Jim and Walter to a farmhouse, where soft-spoken Mary Malden invites them in. Although Mary insists that she lives alone and has not seen anyone that night, Walter searches the house for clues. When Walter reports finding men's clothing in an upstairs room, Mary admits that her brother sometimes stays with her, but has been gone for a few days. The rifle-toting Walter demands to know where her brother is, but Jim, who has deduced that Mary is blind, suggests that they continue their search outside. Jim soon comes back inside, and he and Mary talk about loneliness and trust. Mary thanks Jim for not pitying her and, after insisting that he and Walter stay the night, confesses that her disturbed brother, Danny, is, in fact, hiding on the farm. Promising to protect Danny, Jim persuades Mary to talk to her brother about surrendering. At dawn, Mary slips out of the house and brings Danny, who is hiding in the storm cellar, some food. Although Mary convinces the confused teenager to "go away" with Jim, Danny runs off when Jim discovers them. Jim chases Danny to a shack, and there, while holding Jim at bay with a knife, Danny alludes to the fact that Mary passed up a sight-saving operation to stay with him after their mother died. Just as the unarmed Jim is about to grab the knife, Walter bursts in and fires a shot at Danny. Jim wrestles with Walter, knocking the rifle to the floor, and Danny takes off with the weapon. Jim and Walter pursue Danny to a rocky cliff and, while struggling to reach the top, Danny slips and falls to his death. Upon seeing Danny close up, Walter cries out that he is "just a kid" and carries his body to a nearby house. Later, a grief-stricken Mary says a tearful prayer over Danny's body, then stumbles back to her own home, followed by Jim. When Jim asks her about the eye operation, Mary admits she is afraid to try it, because its failure would mean the end of all hope. Crying, Mary begs Jim to leave her alone and, defeated, Jim heads for the city. As he nears his home, however, Jim reflects on what others have said about loneliness and need. Unable to return to his old life, he drives back to Mary, who embraces him with love.