Set in the homestead kitchen of Bain's station, The Black Horse sees 17 year-old Walter Bain spending his last week of the holidays at home. Much of his life to this stage has been spent at a boarding school, a decision made by his over-protective mother, Rhoda, and very much against the wishes of his father, Harry, a hard man who has battled the land and everything it has thrown at him from early childhood. Having risen long after the station's day begun Walter admits to his mother and housekeeper that he finds it hard to re-adapt to life at home, preferring to spend his time on the verandah reading. However, despite his mother's attempts to drive him towards any profession away from the land, Walter would prefer not to go back to school - a place where 'most of the fellows... are such kids compared to' him.
When Harry Bain enters the kitchen he attempts to re-ignite the spark that his son had as a child by challenging him to break in the new black colt. Although only recently acquired the horse has come to be regarded by the station men as bad news, and a danger to all concerned. Harry is more concerned with his son showing his metal than with any danger the colt may cause. After Walter exits the kitchen Harry and Rhoda argue, leading Rhoda to describe him as tough and brutal, and proposing that any man who's callous about himself isn't likely to have much sympathy for anyone else. In the midst of their argument news comes that Walter has been hurt. When he is carried in to the kitchen he appears to be okay. On being told what happened Harry is hit with guilt and exits with his rifle. Meanwhile Rhoda explains to Walter why she has always tried to push him away from the station life. Walter also admits that the accident was his fault - he's got out of the habit of handling young horses - and asks that the colt not be punished. A gunshot is heard, however, just as Walter begins to fade. Harry returns to the kitchen and is forced to confront the tragic result of his unbending nature.