Walter Vale (Richard Jenkins), a widower and college professor in Connecticut, fills his bored days by pretending to work and attempting to learn to play the piano. But when he's forced to attend a conference in New York, Vale returns to his old apartment to find a young couple—Tarek (Haaz Sleiman) and Zainab (Danai Gurira), illegal immigrants from Syria and Senegal, respectively—living there. After the awkwardness of the misunderstanding passes, a friendship develops between the three of them, and they become oddly matched roommates.

Vale—who's on a vague self-improvement trajectory in the wake of his wife's death, searching for something else that elicits passion in himself—becomes fascinated with the African drums that Tarek plays, and the young man begins teaching the flabby old square some rhythm. Just as things are looking up for everyone, Tarek is picked up by the cops over a minor incident in the subway and placed in an immigration detention center, where he's confronted with the bureaucratic frustrations of an unsympathetic system. By the time it ends, The Visitor changes from being a portrait of disparate people to becoming an affecting look at the sinister bureaucracy of post-9/11 immigration control.