Nemesis

"An agent must pursue a dangerous fugitive in the wilderness after he escapes a car accident. After a woman appears lost in the woods, the agent suspects she's up against them both."

A car wreck allows a fugitive recovery agent's serial killer prisoner to escape into the wilderness, so she's forced to pursue him. The other driver involved finds the agent while lost in the woods and initially, the female stranger's presence complicates matters, but when the agent suspects her involvement wasn't by chance, the killer intervenes, revealing they were working together as killer and cleaner. They capture the agent, but she escapes. The agent eventually manipulates and regains some control of the situation, setting the stage for a fatal confrontation.