Synopsis for
The Strangers (2008)

A young couple staying at a summer retreat are faced with a night of psychological terror. As the night goes on, the reality of what will come is more terrifying than anything both could have imagined.

Since the narrator in the beginning concludes his monologue with, "The brutal events that took place there are still not entirely known" we can only assume that both James and Kristen do not live to tell their story.