I suppose it’s played like a game though the urgency suggests that the threats are real. Â But how can a half-dozen people locked in a 15’Ã—30′ room really qualify as a civilization? Â No matter. Â When we detect the interlopers down the hall, we get the door slammed and barred before they can see us. Â But they know that we’re in here and they’ll try anything to get in. Â Just as we are prepared to make any sacrifice to keep them out. Â We grab rocks, bricks, blocks of wood â€” any kind of shim we can find in the closet and jam them under the door, anything to seal it up. Â Out in the hall we can hear them trying to work their way in. Â They’re trying to lower the floor. Â We hover near the door, holding our bodies up against it like that will make some difference. Â The room is filling with water? Â The water rises. Â We dive down to ensure that the shims are still lodged under the door crack. Â A hand comes through from the other side, we grab it and go at it with a bow saw. Â Cries of pain, the arm recoils. Â The water recedes some but there is damage and one of us has drowned. Â We wait for cries or even shuffling from the other side but it seems they have retreated. Â We are loathe to re-open the door.