Watch full movie online. One of the 12 Westerns in 12 Months; Travers, a doctor who deserted his military post, searches the frontier for the wife who left him. His quest is thrown off course when he saves Sarah, a woman left for dead after a wagon raid. With the cavalry, the law, and deranged outlaws on their trail, Sarah and Travers set off together to find this missing woman. Heart of the Gun is a psychological thriller and a romance drama wrapped in a gritty Western setting.