Gary King

Dana is failing Biology. To pass she must attend an extra credit assignment with several classmates that will lead them into a remote region of the Great Dismal Swamp, a place teeming with life... and death. While the group keeps one eye out for hungry bear, deadly snakes and lurking gators, they are unaware of the real danger. For the top of the food chain lives in a dingy cabin not too far from their campsite, and he has an appetite for human flesh. (imdb)

After the mysterious death of their young son, a couple desperately flees to a remote lake house to escape the unrelenting haunting following them only to discover the mysterious entity is still very much a part of their lives.