The Key plot
Five friends go into a large abandoned building to make a documentary about the dark past: it is said to be haunted. But they soon discover that the leader of the group has other plans: he brought them here because there is said to be a treasure hidden somewhere, which was left by his grandfather, a Freemason. The visitors discover that there is indeed a curse on the big house. When one of them opens a certain door, a demon is released with it and they realize that they have opened a gate of hell. Can any of them survive now?