The sole element of magical realism in Mohsin Hamid’s “Exit West” — a novel that follows a pair of refugees across the world in the midst of a period of mass migration — is a series of doors that lead directly from one country to the next, which are utilized in such a delightfully understated way as to reveal their import very slowly — and even in the end, not explicitly. Rather than a scene of caravans and dangerous voyages, we get sent to a series of clandestine agents who can guide one to where the magical door has opened in the basement of a tenement, letting us walk out of a burning middle-eastern city and suddenly appear in an abandoned bedroom in London. On either side of the door, we experience the utter realism of a refugee crisis. At first, the device appears almost superfluous, perhaps even distracting — what’s the point of this device in a world where real population flows are taking place all the time, by even more dramatic means? But as the scale of migration swells and we see the social change that falls out from it, we’re left with a beautiful message about how contingent our social structures are on a few psychically insignificant physical barriers. Overcome by migrants, London develops into a massive social works project that guarantees refugees 40 meters and a pipe. California experiments with competing forms of democratic representation for non-citizens in a society going through a kind of jazz age of cultural fusion. These developments are always taking place in the background of what is foremost a love story between our two heroes, and so the import of the doors themselves and the revolutions they cause is almost easy to overlook in the stream of things. But there’s something very valuable being said about how significant a few physical laws and barriers are to shaping the world’s social possibilities. Tweak even a little thing, put a couple of small portals in the world through which migration becomes simple, automatic, possible for whoever truly needs it, and our social structures would turn on their heads. The social consciousness of the planet is informed by a few walls, a few borders, a few seas and deserts, and who could say what we would be capable of if it were just as simple as the people who needed to leave a place walking through a door and finding themselves where they had to be.