Open Grave is a movie about a group of five people awaking in a mass grave. They don't know how they got there, and slowly realize, they don't know who they are either. The only one who seems to have any answers, is unable to speak. The movie opens with the last of the five regaining consciousness. After a time, the last man is able to get out of the pit with the help of a woman who doesn't speak. She leads him into the woods to a mansion, where he meets the rest of the group.
Eventually, they find a clue to their identities upon discovering their respective driver's licenses, and are able to match their faces to the names.
As time progresses, snippets of memory return, creating a nagging sense of deja vu. The group must learn to survive together while still piecing together their pasts. The biggest hurdle they must overcome is learning to depend on each other, while making sense of their situation.