In the Line of Duty 4 (1989)

In the shadowy underbelly of international organized crime, two detectives find themselves in the throes of an intricate drug-trafficking conspiracy that seems to have tendrils reaching out from the depths of the underworld. The relentless and headstrong duo, Donny and Penny Yeung, are as much at odds with each other as they are with the situation they find themselves in. Their investigation takes an unexpected turn when an innocent immigrant dock worker, Luk Wan-Ting, becomes an unwilling pawn in this dangerous game of chess. Luk, a mere bystander in this deadly game, is thrust into the limelight when he witnesses the gruesome murder of an intelligence operative. Framed for a crime he didn't commit, Luk finds himself on the run, with the haunting images of his friend's vicious assassination by hired killers trailing him. As he loses a crucial film negative in the chaos, he is left with no choice but to escape to Hong Kong. As the layers of the mystery continue to unravel, Donny and Penny are tasked with the delicate mission of extraditing Luk back to the United States. The pairs' differing perspectives on Luk's innocence create a fiery dynamic, with Penny fervently working to clear Luk's name while Donny remains steadfastly suspicious. As they delve deeper into the case, they unearth possible links to rogue CIA operatives and corrupt cops, muddying the waters of their investigation and casting a shadow of distrust over their own department. Now, caught in a twisted web of deceit, they face a race against time. Over the next 72 hours, Penny and Donny must set aside their differences to shield Luk from the relentless assassins who want him silenced. As they navigate through this labyrinth of danger, they must outwit their enemies, protect their witness, and unravel the truth. But can they survive this case without destroying each other first? In the murky world of crime and corruption, trust is fleeting, alliances are transient, and survival is anything but guaranteed.

In the Line of Duty 4 is an action movie featuring Cynthia Khan and directed by Yuen Woo-ping.

In the Line of Duty 4 is currently streaming for free (ad-supported) on Cineverse, Freevee, Midnight Pulp, Plex, Plex Player, The Roku Channel and Tubi TV and it's also available on fuboTV.

It is also possible to buy In the Line of Duty 4 on Amazon Video.