It's time to talk about networks.
The Doors form a network. You can walk through one Door and emerge out of another. How do I know this?
I am driving through the rain when I see it. There's a metal staircase beside a building that leads to a door...and another Door. I remember the markings. I can see it, practically taste the other side. I hurriedly park the car, slam the door shut, not even bothering to lock it, and rush up their steps. I take the door handle, fervently wishing that it won't be locked, and am surprised and relieved when it isn't.
I turn the handle and walk through. On the other end is a sandy beach, the night sky overhead. The Door shuts behind me before I can stop it.
It's three hours before I find out that I'm on the Ivory Coast.