Philip Marcus [David Naughton] and Alexandria 'Alex' Marcus [India Allen] are a married couple who decide to spend a vacation at a friend's house in the Arizona desert, hoping to reconnect as their relationship has strained under Philip's demanding work that has kept him away. Alex feels lonely, and a close friend even hints that she should consider an affair, a thought that troubles her as Philip remains too preoccupied to give her attention, prompting them to push toward a night bar.
At the bar, the couple quickly run into trouble with a biker, but Randall Murphy [Gary Hudson] and Maggie [Michelle Moffett] intervene and give them a ride to a trailer park. Randall is there with a darker purpose: revenge against his ex-girlfriend Celeste [Kathy Shower], who had sent him to jail, and Maggie is a prostitute Randall has brought along.
Randall breaks into Celeste's trailer, terrifying Celeste. Despite his assurances that he is not there to harm her, he forces Celeste to have sex with Maggie, who eventually shoots and kills Celeste at Randall's request. The next morning, the couple arrives at Alexandria and Philip's vacation home, as Randall had promised to help Philip look for plants for his job. The two men leave to search for plants, only for Randall to push Philip off a cliff. Believing the man dead, Randall drives away, unaware that Philip has survived and is now making his way back to rescue his wife.
Meanwhile, Alexandria grows increasingly suspicious that Maggie is a wanted criminal, and at one point tries to call the police, but is interrupted by Maggie. When Randall returns without Philip, Alexandria—driven by a mix of survival instincts and a dangerous, alluring attraction—tries to turn the couple against one another by having sex with them both. After sleeping with Randall and discovering she enjoys it, Alexandria attempts to run away with him, but the plan falls apart.
On his way back to the house, Philip discovers Celeste's naked dead body in her trailer park, and is later found by Sheriff Brenner [Paul Gleason], who takes him back to the vacation house. They sneak inside in an effort to save Alexandria. Maggie, who has decided not to follow Randall, is accidentally shot by the sheriff, who is then killed by Randall. Randall then pursues Alexandria, who ultimately turns the tables and shoots him. At last, Philip and Alexandria are safe and share a quiet, relieved embrace.
