The Virginian (1962)

S01E22 Vengeance is the Spur

A mysterious woman named Mrs. Francis (Nina Foch) arrives in Medicine Bow, seeking the Virginian's help to find her friend, Michael O'Rorke (Michael Rennie), the ex-foreman of Shiloh who now leads a life on the run in the badlands. She suspects her husband, falsely accused of murder, is hiding with O'Rorke's gang. However, it soon becomes clear that Mrs. Francis is not who she appears to be, and her arrival brings unexpected turmoil.