Dallas private eye Bat Garrett is hired by wealthy Texas oilman Frank Gaston, who thinks someone is trying to kill him. Bat is skeptical but when Gaston is found dead, slumped over at his desk, the fear seems to have been well-placed. Darla Gaston, the beautiful young oilman's daughter, is encouraged by her lawyers to fire Bat and let the police investigate. Darla, however, wants Bat to find out why her father has been calling a number in Colorado for several years. Bat discovers that Gaston has left a trail of lies and deceit, bigamy, and maybe even a decades-old smuggling operation involving children and a massive real estate deal in Oak Cliff. It's the biggest case Bat's ever had, but it may cost him more than he's ever had to give.