The Guest follows the story of Daru, who is a schoolteacher in a remote plateau region. The area has gone through a draught, but recently a blizzard has passed through, leaving everything covered in snow. This has kept away Daru's pupils.
The narrative opens as Daru watches two men approach his schoolhouse. He watches them climb the hill. One of the men, a gendarme named Balducci, is very familiar to Daru. He leads an Arab prisoner who has been accused of murdering his cousin in a family squabble. Balducci has been ordered to bring the Arab to Daru, and then return immediately to his post. Likewise, Daru has orders to turn in the prisoner to police headquarters at a town approximately twenty kilometers away. Daru refuses this task, considering it dishonorable. Balducci agrees with the schoolmaster, but insists that in war men must be prepared to do many different jobs. The gendarme is insulted by Daru's stubborn refusal, and leaves in anger.
Daru feeds the Arab and spends the night sleeping in the same room as the prisoner. During the night the Arab gets up for water, and Daru mistakenly thinks he has escaped. The next day Daru leads the Arab to a point on the plateau, and equips him with money and food supplies. He points him in the direction of imprisonment, and then also points him in the direction away from police headquarters, where he will find shelter with the native people. He leaves the Arab with the choice, but when he looks back, he is upset to see the Arab ultimately chooses the direction leading towards imprisonment. The story ends with Daru looking out the window of his schoolhouse.