What is the plot of "Dusk" by Saki?

The story opens with Norman Gortsby sitting on a bench in
a park in London. It is early March and dusk is setting in, and this pleases Gortsby who
sees dusk as "the hour of the defeated" when men and women who had suffered some kind of
failure came out when the evidence of their failure would not be noticed or commented
upon. We are told that Gortsby himself has failed, but in a "more subtle ambition" that
is never disclosed.

On the bench next to him is an old
gentelman who fits Gortsby's category of those people who come out at dusk. As he moves
on, his place is taken by a young man who sits down, uttering a loud expletive. When
asked, the young man tells him that he arrived in London that afternoon to find the
hotel he was going to stay in had been knocked down. He went to another hotel, then went
out to buy some soap, but forgot the name and address of his new hotel. Gortsby tells
the young man he had done the same thing. The young man obviously expresses the hope
that Gortsby will lend him some money. Gortsby says that the weak point of this young
man's story is that he can't produce the soap, and Gortsby sees this as proof that the
young man is trying to trick him. The young man walks off
angrily.

When Gortsby himself gets up to move, he looks
down and sees a block of soap that he assumes must have fallen out of the young man's
pocket. Chagrined, he finds the young man, giving him the soap and also a sovereign. The
young man is surprised and rushes off, and Gortsby assumes he is overwhelmed by emotion.
Gortsby concludes that he must not be too quick to judge by circumstances. However, when
he goes back to the bench, he sees the first old man who was sitting next to him,
looking around the floor around the bench. He tells Gortsby he is looking for his
soap.