Mr. Woodifield is a retired, older man who ventures out of his home once a week, on Tuesdays. He has had a stroke, which has presumably led to his retirement. He very much wants to remain relevant, and he enjoys visiting his friend, referred to as "the boss," who is five years older than Woodifield and is still on the job.
The boss is a proud man who enjoys showing off his office, which has been recently refurbished, to the envy of Mr. Woodifield. He and Woodifield have both lost sons in the war, and their sons are buried in Belgium.
Macey is the office messenger, and he, too, is not young. He does the bidding of the boss.
The titular character, the fly, falls into the boss's inkwell. After initially helping it by lifting it out, the boss tortures the fly by shaking ink onto it until he kills it.
The point of view of the story is third-person.