Colton, a former Union Cavalry captain, spends the years following the Civil War wandering from town to town in the American West, meeting old friends and strangers alike and helping them to solve their problems while trying to find himself.
The show followed the basic format of other Western shows such as Have Gun – Will Travel and Maverick, but added Serling's trademark philosophical qualities in an attempt to make a Western series for more mature viewers. CBS wasn't happy with the focus on ideas over action, however, and when ratings failed to meet expectations the show ended up being canceled at the end of its lone season.
Tropes associated with this series include:
- Badass Preacher: Jack Lord plays one in "The Vespers".
- Berserk Button: Hurting or disrespecting the vulnerable (particularly women) is a big one for Colton.
- Beware the Nice Ones / Tranquil Fury: Colton is rarely seen speaking above a normal pitch, but he does get mad, and lord help you if you find yourself on the receiving end of his anger.
- Gray-and-Gray Morality: One of the things that distinguished The Loner from the rest of its genre. There were good guys and bad guys, but all characters were typically allowed to speak their mind and express their own motivation.
- Heroic BSoD: Colton suffers one after killing a teenage Confederate soldier is in his backstory. The colonel in "One of the Wounded" is nearly catatonic as a result of his own wartime trauma.
- Instrumental Theme Tune: Composed by Jerry Goldsmith, who also scored the episodes "An Echo of Bugles" and "One of the Wounded".
- Just a Flesh Wound: Colton tries to avoid killing people if he can help it, and is a good enough shot that he can incapacitate his adversaries with a nonlethal wound.
- Maligned Mixed Marriage: "Widow on the Evening Stage" involves the family of a man recently killed by an Apache war party rejecting his newly-arrived wife and their son (whom they had never seen before) because she is Native.
- Powder Keg Crowd: Discussed in "Widow on the Evening Stage":"If you stick good men into a mob... take away their names, faces, identities — take away their responsibility, they are no longer good men!"
- Shell-Shocked Veteran: Colton
- Walking the Earth: Colton continually roams from one place to another.