Lockbox

Two estranged siblings inherit their grandmother's home after her death, but as they work to clear out the old home, they find themselves trapped inside behind a door with eight deadbolt locks... and the world outside the home is plunged into unnatural darkness. The house descends further and further into a surreal nightmare as the siblings desperately search for the keys that will open the way back to reality, but their mutual anger and distrust threatens to doom them to eternal imprisonment in this house that is not merely a house, but a trap for human souls.