Walter Deaney, John Saxon, a trade union lawyer, shoots and kills a burglar in his own home, an act that triggers a tense chain of investigations. To keep Mitchell away from Deaney, Chief Albert Pallin, Robert Phillips, orders the relentless plainclothes detective to stake out the home of James Arthur Cummings, Martin Balsam — a wealthy man with deep mob ties whose empire revolves around the import and export of stolen merchandise. Mitchell, Joe Don Baker, begins the assignment with a cautious focus on Deaney, yet the case widens when Cummins himself becomes a pivotal figure in the unfolding criminal web.
Cummins’ world begins to intrude when Salvatore Mistretta, Morgan Paull, cousin of mob boss Tony Gallano, is caught in a scheme to bring in a shipment of stolen heroin from Mexico without Cummins’ blessing. The tension between legitimate business and criminal leverage pulls Mitchell deeper into the underworld, where power, loyalty, and money blur the lines between cop and conspirator. During this period, a glamorous escort named Greta, played by Linda Evans, arrives at Mitchell’s apartment. He lets her in, and after two nights with her, arrests her for marijuana possession, only to learn that Deaney is paying Greta $1,000 a night to entertain him. The deception takes a sharper turn when Deaney attempts to bribe Mitchell with Greta’s services and an illicit real estate deal, revealing the extent he’s willing to go to neutralize the persistent detective.
As the plot thickens, Deaney enlists Cummins in a dangerous scheme to remove Mitchell from the equation. They take to the dunes in dune buggies; in a high-stakes pursuit, Mitchell fights back, killing one of Deaney’s henchmen with a rock while Deaney’s own off-road craft crashes in a chaotic finale, ending his threat. Cummins, meanwhile, refuses to allow Mistretta to use his port facilities, prompting Gallano to send thugs to harass Cummins. With his own freedom at stake, Cummins enlists Mitchell as a covert ally, proposing that Mitchell pose as a chauffeur to intercept the shipment, seize the drugs, and arrest Mistretta. What starts as a calculated alliance, however, quickly devolves into a dangerous double-cross: Cummins tips off Mistretta about Mitchell’s true identity and replaces the heroin with chalk, turning the operation into a trap.
Mistretta, furious at being outmaneuvered, resolves to kill Mitchell and dispose of his body on Cummins’ boat. The plan spirals as Mitchell triggers a car explosion and escapes, pursued by Mistretta’s men. A police helicopter soon arrives, dropping a gun to aid Mitchell, who then proceeds to kill Mistretta and his associates. With the drug shipment thwarted, Mitchell closes in on Cummins, who is attempting to flee the country by sea. The pursuit culminates as the helicopter drops Mitchell onto Cummins’ boat, where he confronts Benton, Merlin Olsen, and ends Benton’s resistance with a gaff hook. Cummins’ final gambit fails when a close-range rifle shot ends his bid for escape, bringing the central plot to a dramatic close.
With the immediate danger resolved, Mitchell returns to his apartment to find Greta waiting. He bluntly notes that she is no longer paid to keep him company, yet Greta, Linda Evans, still hopes for one more night together. The tension loosens into a wry, almost humorous beat as Mitchell detects a marijuana scent on Greta, and the film closes on the prospect of arresting her for a second possession charge. In the tail end of the night, the balance between law and crime remains precarious, underscoring a world where deals, double-crosses, and a lone detective’s stubborn pursuit of justice intertwine in a tense finale.
