Mary Lou manages to escape abduction by a prostitution ring. She tells the Chief of Detectives they were planning to take her to the Berrywood road house, a well-known den of iniquity. Jim Murray and beautician Belle Harris are using her beauty shop to recruit floozies for their road house circuit. Dona Lee, who works at the beauty salon, is falling in love with young reporter wanna-be Phillip, but Murray gets jealous and makes life rough for him. Meanwhile Dona begins to figure out the racket, but becomes threatened by Murray's unwanted advances.

When Jim Allen is lynched, his identical twin brother Bob, a Texas Ranger, takes his place in an attempt to flush out the man responsible.

The fourth of 12 singing Westerns starring the "Silvery-Voiced Baritone," Fred Scott, Melody of the Plains begins peacefully enough with Scott, as cowboy Steve Condon, warbling Don Swander and June Hershey's "Albuquerque." The story quickly takes a rather grim turn when one of Steve's colleagues is shot and killed after selling out to a gang of rustlers. Mistakenly believing he fired the deadly shot, a dejected Steve, along with sidekick Fuzzy, goes to work for Bud's father, a rancher nearly forced into bankruptcy by a crooked land developer.

A Florida-bound train is filled with romance and intrigue when one of the passengers disappears while carrying $11-million in unset jewels.