A Texas Ranger turns deputy sheriff; a woman wants him to kill her cattle-baron husband.

The first of the five films where Bill Elliott played a detective lieutenant in the L.A Sheriff's department, Dial Red "O" (the correct title with the number 0 (zero), as on a telephone dial, shown in ") opens with war-torn veteran Ralph Wyatt getting word that his wife is divorcing him, and he flees the psychiatric ward of the veteran's hospital, wanting to talk to her. His escape touches off an all-out manhunt, led by Lieutenant Andy Flynn of the sheriff's department.