Saki opens his story "Dusk" with a description of the poor people who come out after dark because they are ashamed to show themselves by daylight. They are described from the protagonist Norman Gortsby's point of view.
The scene pleased Gortsby and harmonised with his present mood. Dusk, to his mind, was the hour of the defeated. Men and women, who had fought and lost, who hid their fallen fortunes and dead hopes as far as possible from the scrutiny of the curious, came forth in this hour of gloaming, when their shabby clothes and bowed shoulders and unhappy eyes might pass unnoticed, or, at any rate, unrecognised.
Gortsby views these people without sympathy and perhaps with mild contempt. The purpose of this description of all the "defeated" people is to serve as contrast with the young con-man who is posing as a member of the country gentry. At first Gortsby does not believe the stranger's story, but when he finds the bar of soap which seems to prove the other man was telling the truth, Gortsby rushes after him.
Lying on the ground by the side of the bench was a small oval packet, wrapped and sealed with the solicitude of a chemist's counter. It could be nothing else but a cake of soap, and it had evidently fallen out of the youth's overcoat pocket when he flung himself down on the seat. In another moment Gortsby was scudding along the dusk-shrouded path in anxious quest for a youthful figure in a light overcoat.
Once Gortsby believes that the other man belongs to a higher social class than himself, he is anxious to do him a favor. He is hoping to win a friend who might help him rise in the world. That was the bait the con-man was dangling when he told his story. He said he was a stranger in London in order to suggest that he would be happy to make a friend his own age who knew his way around. The con-man was smart enough to know that people in general are willing to help those above them and not those beneath them. This is because people are motivated by self-interest. Gortsby is lending the stranger a sovereign because he hopes to make a friend of this self-styled member of the landed gentry. Gortsby envisions being invited to a country manor for "shooting" or "riding" and meeting other upper-class types.
This truth about human nature is noted by Jaques in Shakespeare's As You Like It.
"Poor deer,' quoth he, 'thou mak'st a testament
As worldlings do, giving thy sum of more
To that which had too much." (II.1)
The contrast between Gortsby's attitude toward "the defeated" at the beginning and his attitude toward the con-man at the end highlights Saki's thesis that people are eager to help those above them in social status and often make fools of themselves when they do so.