[it feels good to laugh, and even better to be trusted. Norman feels something in his chest loosen at the feeling - relief? hope? gratitude - and follows Steven into the Arcade. Once they're both inside, he locks the door and opens it once more- now it's looking out over Lake Dala, the view from the front door of Hill House. he closes it once more, freeing it up for anyone else who might need it]

No, as far as I can tell it's portable quantum physics ... this door can connect to almost any door in the peninsula while it's open. When it's closed, the last door it connected to goes back to itself.

... Though if I start seeing stray socks around, I suppose we've solved one of the great mysteries of the world.