Brothers Joe and Paul Fabrini eke out their living as wildcat truckers, barely keeping ahead of their creditors. Joe is stubbornly independent, determined to save enough money to establish his own trucking business, while Paul is disenchanted with life on the road and wants to settle down with his wife Pearl. Consequently, when Ed Carlsen, the big-hearted owner of the Carlsen trucking company, offers Joe a job, Joe refuses, and Paul, out of loyalty to his brother, continues his life on the road. On the night that the brothers make their final payment on the truck, an exhausted Paul falls asleep at the wheel, sending the vehicle careening over a cliff. In the accident, the truck is demolished and Paul loses his arm. Hearing the news, Ed's sarcastic, shrewish wife Lana, who is in love with Joe, convinces her husband to offer him a managerial job in the office and Joe, now the sole support of his disabled and embittered brother, accepts. Lana continues her obsessive her pursuit of Joe, but he is in love with Cassie Hartley. When he refuses Lana's brazen advances at a party, using the excuse that he will not betray his good friend Ed, Lana drives her drunken husband home, and when he is too drunk to get out of the car, she decides to leave him with the motor running. Ed is asphixiated, but his death is ruled accidental. With her husband dead, Lana offers Joe a partnership in the business, but when she discovers that Joe is planning to marry Cassie, she accuses him of driving her to commit murder. The district attorney believes Lana's story and charges Joe as an accomplice in Ed's murder. Lana is soon haunted by her crime and begins to lose control of herself. When she is called to testify at Joe's trial, she breaks down on the witness stand and rants insanely about Ed's death. Joe is then freed and returns to Cassie and the trucking company.