When a flood of lawless gunmen invades his once peaceful town, Marshal Cass Silver (Robert Ryan) knows it's up to him to force them out. But the only chance he might have is to gain the help of a gunslinger named Thad (Jeffrey Hunter), who wrongly believes the Marshal is responsible for his father's death. To save the town, Silver will have to earn the aid, and trust, of a man sworn to send him to his grave!