Trooper O'Brien is a 1928 Australian silent film from the team of John and Agnes Gavin. It was a melodrama set during the "Ned Kelly era" about an orphaned girl raised by a policeman in the bush. It is one of the rare Australian films that still exist in its entirety. The film begins with Mr Alston telling his son John that he does not approve of his marriage and wants nothing more to do with him. After Mr Alston goes back inside the house Mrs Alston speaks with her son and gives the granddaughter Winnie a parting gift of a trinket. Mr Alston Jr then leaves with his wife and daughter and changes his surname to Brown. About 3 years later the now Mr Brown, his wife and daughter are living in the bush. There is a fire and they have to flee the area. As they flee they crash their wagon. Mr and Mrs Brown die in the accident but their daughter Winnie survives and is found by two boys, Glen O'Brien and his Aboriginal friend Moori. Winnie is taken back to Glen's house and because her parents are dead and there is no way of tracing any other family she lives with them. As the years pass Glen O'Brien follows family tradition and pursues a career in the police force. Before leaving for Sydney he proposes to Winnie. In Sydney Glen O'Brien attends a house where Mr and Mrs Alston are being robbed. He arrests the robbers along with the help of his childhood friend Moori. Back in the bush Glen returns and marries Winnie. While there he takes Winnie back to the spot where he found her as a child and they discover a metal box. Glen receives a visit from Mr and Mrs Alston who have come to thank him for his assistance. Before the Alston's leave Glen shows his father the metal box. His father tells him that years ago he found some items of the dead woman Mrs Brown. His father uses the key to open the metal box and inside they find the trinket. Mrs Alston sees the trinket and immediately knows that it is the one she gave to her granddaughter. It is at this point that Mr and Mrs Alston realise that Winnie is their granddaughter.