A innocent dentist is murdered and the only apparent motive seems to be to steal a set of dental x-rays. To the police it looks like an accident, but private eye Brad Runyan thinks there's more to it.

Marian Forbes has been having an affair with her boss and when he drops her for another woman. In an act of jealousy and greed she convinces an acquaintance to murder her former lover and then impersonate him just long enough to get their hands on a large sum of money.

Down-and-out artist Joe Manning wakes up from a night of drunken revelry in a jail cell, where he's being held on suspicion for the murder of a nightclub singer.

Having fled to Mexico from the U.S. many years ago for killing his father's murderer, Martin Brady travels to Texas to broker an arms deal for his Mexican boss, strongman Governor Cipriano Castro. Brady breaks a leg and while recuperating in Texas the gun shipment is stolen. Complicating matters further the wife of local army major Colton has designs on him, and the local Texas Ranger captain makes him a generous offer to come back to the states and join his outfit. After killing a man in self-defense, Brady slips back over the border and confronts Castro who is not only unhappy that Brady has lost his gun shipment but is about to join forces with Colton to battle the local raiding Apache Indians.

Set at the beginning of the Civil War, Tap Roots is all about a county in Mississippi which chooses to secede from the state rather than enter the conflict. The county is protected from the Confederacy by an abolitionist and a Native American gentleman. The abolitionist's daughter is courted by a powerful newspaper publisher when her fiance, a confederate officer, elopes with the girl's sister. The daughter at first resists the publisher's attentions, but turns to him for aid when her ex-fiance plans to capture the seceding county on behalf of the South.