On Dangerous Ground is a 1951 film noir-melodrama starring Robert Ryan and Ida Lupino, directed by Nicholas Ray, and produced by John Houseman. The screenplay was written by A. I. Bezzerides based on the 1945 novel Mad with Much Heart, by Gerald Butler. Co-star Ida Lupino made her uncredited directorial debut shooting scenes when Nicholas Ray was unavailable. Plot Embittered inner-city police detective Jim Wilson is disgusted with his job and the night-crawling people it draws him into relentless contact with. Known for beating information out of suspects and witnesses alike, he is sharply warned to tone it down by his chief. Immediately ignoring him, Wilson is then relegated to an up-state case to cool off. He joins it mid-manhunt, pursuing the murderer of a young girl across sunny snow covered fields and patches of forest. The chase is led by an unhinged Walter Brent, the father of the victim, who is determined to exact deadly vengeance. Stuck together, Wilson and Brent get separated from the posse and track the suspect to a remote house. There they find Mary Malden, an attractive young woman, alone in the home. She relates she lives with her younger brother, Danny, who is somewhat "off". Slowly both men realize on their own that she is blind. Mary appeals to Wilson on behalf of Danny's mental illness. Taken by her earnestness and lack of self-pity, he agrees to protect the boy from Brent and arrest him peacefully. The two men end up spending the night in front of Mary's fireplace. At dawn Mary slips out of the house and goes to the storm cellar where Danny is hiding. She tells him that Wilson is a friend and will take him away to be helped. On her way back in, she and Wilson get into a confrontation and Danny flees the cellar. Wilson trails him to a secluded shack and calmly engages him in conversation. Danny rambles about not wanting to kill the girl while Wilson slowly advances and prepares to seize him. Before he can, Brent bursts in and the two men brutally struggle. Brent's gun fires during the tumult and Danny escapes. The men chase Danny up a rugged stone outcropping, where Danny loses his grip and falls to his death. Brent carries his body to the nearest home, remorseful upon discovering the teenage Danny's youth. Mary arrives, having heard the gunshot. She absolves