Backfire (1988)

"Before the night is over... someone will be rich, someone will be dead, someone will be avenged."

Mara McAndrew's marriage is falling apart. Her husband, Donnie, a Vietnam veteran, suffers troubling flashbacks about the war, leaving him unresponsive to her needs. Mara wants out, but she also wants Donnie's money. When Mara meets a mysterious stranger, Reed, at a local bar, she believes she has found the right person to help her out of her predicament. But Mara worries that Donnie's sister, Jill, is on to her.