No Way Out (1987)

Kevin Costner, Gene Hackman and Sean Young star in a neo-noir suspense thriller with espionage elements. Costner's navy commander hero and Hackman's secretary of defense are caught up in a sordid love triangle with Hackman's mistress, played by Sean Young. Hackman finds out about Young's duplicity and murders her in a blind rage, having been witnessed earlier at the scene by the third man who the audience can see is Costner. Hackman enlists Costner to help cover it up and find the "real killer", a suspected KGB sleeper agent. However, Hackman doesn't know that Costner was the man sleeping with Young. Meanwhile, Hackman's second-in-command, a fixer played by Will Patton, discovers a negative of a photograph Young took of Costner linking him to the scene of the murder. Therefore, a race against time ensues for Costner to find evidence linking Hackman to Young while they wait for the photo to develop so as to ensure he can defend himself against being charged with both murder and espionage.

Took a while to get going but the payoff is worth it. Incredibly suspenseful stuff with plenty of twists and turns as it builds to a crescendo. Costner is serviceable, and Hackman is brilliant as always, but the star of the show is Will Patton as Hackman's devoted and enigmatic fixer. Pay attention in the first half as there is some very clever foreshadowing at play.