No Way Out (1987)

Synopsis
No Way Out is told in flashback as Naval officer Tom Farrell (Kevin Costner) is grilled by his superiors regarding a recent "unpleasantness." While at a Washington party, Tom meets Susan Atwel (Sean Young), and they're soon sharing a steamy love scene in the back of a limo (marvelously parodied in 1993's Hot Shots! Part Deux). Several months pass before Tom meets Susan again; he discovers she's the mistress of the US Secretary of Defense David Brice (Gene Hackman). When Susan is murdered by Brice, his loyal aide (Will Patton) dutifully destroys the evidence and invents the fallacious theory that a KGB mole was responsible. Tom is assigned to locate that mole -- a perilous situation, since Tom knows that no such mole exists, but must go along with the charade since he was the last person who was seen with Susan. ~ Hal Erickson, All Movie Guide