Answer:
To mourn the death of his wife.
Step-by-step explanation:
The short story of "In Another Country" by Ernest Hemingway tells the story of a wounded American soldier recovering in an Italian hospital. Nick was the narrator and main protagonist of the story who tells us about the other soldiers.
Among the other wounded soldiers was an old man, a major who had been regularly treated and also seen and interacted with by Nick. But one day, he and the major talked about the idea of marriage which seemed to anger the major. H snapped at Nick and told him that "a man must not marry" and that "If he is to lose everything, he should not place himself in a position to lose that. He should not place himself in a position to lose. He should find things he cannot lose." But then, he later apologized that he was distraught and acted that way because his wife had died. For the next three days, he failed to turn up for the treatment. The reason why he likely stayed away from the hospital was to mourn the death of his wife.