Carrol Jo Hummer Jan-Michael Vincent grows up in a Tucson trucking family that works for Red River, a local produce-shipper. His father, Sam Hummer, drives the road with two steady partners, Duane Haller Slim Pickens and Pops Dinwiddie Sam Laws, and as CJ comes of age he and his dad become partners too. Sam even has the trailer’s lettering re-done to read “Sam Hummer and Son,” a bold symbol of the new arrangement.
CJ begins dating Jerri Kane Hummer Kay Lenz and the two plan to marry, but tragedy strikes when Sam dies and the family business shifts. With the partnership dissolved, CJ enlists by joining the Air Force; he serves in Vietnam, earns respect, and comes home as a decorated veteran who only wants to return to Jerri. The opening scenes show CJ’s plane landing to a hero’s welcome from Jerri and her brother, and the couple quickly marries, starting a modest, hopeful life together.
CJ secures a bank loan to buy his own truck. He and Jerri visit a used-truck lot and buy a repossessed 1974 Ford WT9000 cabover with a Cummins diesel engine, choosing a blue-and-white paint job and the striking name “BLUE MULE”. The sale includes a sense of independence and a dream of leaving debt behind. Back at Red River, CJ climbs into the life of the road again and proclaims over a CB radio that he’s in business for himself, aimed at getting out of hock as fast as possible.
But the reality at Red River changes. The company has shifted into hauling contraband—untaxed cigarettes, slot machines, and other illicit goods—under the watch of a new regime. Duane [Slim Pickens] warns CJ to stay quiet if he wants to keep driving, and a tense confrontation with Clem [Martin Kove], the ruthless ringleader among the dockside enforcers, leaves CJ nursing a bruised ego. Later, on a lonely highway, CJ is pulled over by Deputy Bob [Ron Nix], handcuffed to his own truck, and then brutalized again by Clem and his crew.
CJ can’t find work elsewhere after being blackballed by Red River. Frustrated and angry, he returns to the yard with a shotgun and threatens Duane, who urges him to speak to his boss, Buck Wessle [L.Q. Jones]. Buck agrees to a limited, clean load to Dallas to placate CJ, and Pops Dinwiddie decides to ride shotgun for protection as they set out. Along the way, the trio is attacked by men from Red River, but they fight back and keep moving. As the weeks pass, CJ uncovers the deeper truth: Red River is part of a larger Phoenix‑based conglomerate called the Glass House, a front for organized crime. The trucking fleet is a transportation network for illicit shipments, quietly controlled from the top.
CJ tries to unite other drivers and resist the pressure to haul illegal cargo. He faces brutal retaliation—beatings, vandalism, and cheating—and is eventually framed for the murder of Duane Haller. After an acquittal, the loss of Pops Dinwiddie, who had been driving the Blue Mule, comes into focus. The discovery of Pops’s body at his house spurs a climactic clash between CJ and Buck on the loading docks, where CJ defeats Buck only to be restrained by Carnell (Pop’s son) as revenge erupts.
A few days later, CJ and the other Red River drivers are invited to a Glass House meeting. They’re offered legal work in exchange for continuing deals that mirror the Glass House’s criminal arrangements, but CJ declines and pledges to keep operating on his own terms, rallying the other drivers to resist the system.
That night, a masked assailant crashes CJ and Jerri’s home and sets it on fire. Jerri loses the baby, a devastating blow that leaves both of them devastated. In the hospital, CJ vows to strike back with everything he has. He heads for the Glass House, radioing Deputy Bob to warn them he’s coming. The trail leads to a hail of gunfire as CJ’s Blue Mule is riddled with bullets, yet CJ charges through the guards, crashing through a giant two-story glass sign that bears the Glass House’s mark. The truck and CJ are nearly destroyed, but he survives.
Back on the news, a peaceful trucker strike in Tucson honors CJ’s stand, and CJ’s brother‑in‑law helps wheel him out of the hospital into a parking lot filled with waiting semis. The crowd cheers as the convoy roars to a close, and a subdued Jerri watches from a hospital window, unsure of what the future holds but drawn by her partner’s courage and the uncertain life they now share.
