"After Twenty Years" is set in New York City in the early part of the twentieth century. It is a neighborhood of shops and offices. It is dark and the streets are nearly deserted. The area has the cold, lonely "alienated" feeling of a big city's business district when all the stores are closed and the workers have all gone home. The narrator tells us that it is almost ten o'clock at night. The weather is cold, windy, and wet.
There was now a fine, cold drizzle falling, and the wind had risen from its uncertain puffs into a steady blow. The few foot passengers astir in that quarter hurried dismally and silently along with coat collars turned high and pocketed hands.
The man standing in the doorway of the hardware store looks somewhat sinister. Pedestrians might cross the street to avoid having to pass in front of him. It is not surprising that the uniformed beat cop should stop to talk to him, although we learn late in the story that the cop is the man's old friend and is keeping an appointment they made twenty years ago.
Anyone who is acquainted with the paintings of Edward Hopper, the American realist, would recognize this scene as one that Hopper himself would appreciate for the feeling of loneliness it evokes. It is reminiscent of Hopper's famous painting "Nighthawks," in which three people are sitting around a counter late at night as seen from the outside through the big plate-glass window. This is a big, cold, tough American city which has a strange charm of its own as a result of all aesthetic considerations having been ignored in favor of maximizing profit from each square foot of space. It is a city where friendship is rare, which makes the relationship between the man in the doorway and the man he expects to meet seem that much more important to each of them. We learn later that the man in the doorway has come a thousand miles to meet his old friend, which suggests how rare it is to find friendship in an towering metropolis where friendship is forgotten in the struggle for existence.
The place where the waiting man is standing used to be a restaurant called "Big Joe" Brady's. We can imagine that such a brightly lighted place was loud and noisy. The patrons were mostly men. They were all talking and laughing, having a good time, even singing. Now it has been turned into a store that sells the hardest kinds of merchandise--and there is no light, no sound of talking, or laughter or music. The policeman's job is to see that all the doors in the neighborhood are locked shut because big cities are always preyed on by the criminal element at night.
Trying doors as he went, twirling his club with many intricate and artful movements, turning now and then to cast his watchful eye adown the pacific thoroughfare, the officer, with his stalwart form and slight swagger, made a fine picture of a guardian of the peace.
There is a sharp contrast between the man in the doorway and uniformed cop when they meet. The civilian looks suspicious. The cop is, as O. Henry states, "a fine picture of a guardian of the peace," a symbol of law and order. These two men were friends twenty years ago when they both were young--but they could not be friends now. They have gone down two separate roads in all that time, and the passage of years has changed them.
The man called Bob is standing inside the entrance to the hardware store because of the bad weather. This makes him look is hiding and might have some criminal intention. Why would a man be standing in a doorway in a dark, cold, nearly deserted neighborhood? The bad weather enables the plainclothes detective to keep his face nearly concealed so that Bob won't realize he isn't Jimmy Wells.
About twenty minutes he waited, and then a tall man in a long overcoat, with collar turned up to his ears, hurried across from the opposite side of the street. He went directly to the waiting man.
The reader is also fooled into believing that this newcomer must be Jimmy Wells because he had no idea that the uniformed cop had been the man Bob was waiting to meet. Who else would it be arriving almost on time and seeming to know a lot about Bob from the old days?
“Bless my heart!” exclaimed the new arrival, grasping both the other's hands with his own. “It's Bob, sure as fate. I was certain I'd find you here if you were still in existence. Well, well, well!—twenty years is a long time. The old restaurant's gone, Bob; I wish it had lasted, so we could have had another dinner there. How has the West treated you, old man?”
Bob and the reader both receive the same shock when the two men reach the brightly lighted corner drugstore and Bob learns that his best friend has turned him in. It was too much to expect a friendship to last for twenty years.