The young man who comes and sits beside Norman Gortsby is obviously practicing to be a con artist. Gortsby proves this when he listens to the hard-luck story and then tells him:
"Of course," said Gortsby slowly, "the weak point of your story is that you can't produce the soap."
The young man doesn't even try very hard to explain why he doesn't have a cake of soap, since his whole story was based on the claim that he had lost his hotel when he came out to buy the soap and had left almost all his money in his hotel room, which he wasn't able to find again because he was new to London and had become disoriented. By the sheerest coincidence, Gortsby finds a cake of soap on the ground by the bench after the young would-be con-man leaves in chagrin. Gortsby mistakenly believes that this must be the soap the stranger had come out to buy, but in fact it unquestionably belonged to the elderly gentleman who had been sitting beside him before the other man sat down.
The con-man had fashioned his hard-luck story in such a way that he would seem to be an upper-class country gentleman who didn't know anybody in London. He spoke of foreign travel and used some words that suggested he had been to Eton and Oxford. The plan was to make the "mark" believe he might have a golden opportunity to make a friend of someone of a higher social class who would invite him down to his family estate for shooting and riding and open a world of possibilities for rising in society. And it wouldn't cost the mark anything because the con-man said he only needed a short-term loan.
"In a foreign city I wouldn't mind so much," he said; "one could go to one's Consul and get the requisite help from him. Here in one's own land one is far more derelict if one gets into a fix. Unless I can find some decent chap to swallow my story and lend me some money I seem likely to spend the night on the Embankment."
Since the soap obviously belongs to the elderly gentleman, Gortsby was right in the first place when he assumed that the con-man was lying.
Gortsby was never going to see the sovereign he gave the stranger again. The young man was a liar. He did not deserve help or sympathy. In fact, he deserved to be arrested and sent to jail. That was why he was acting so nervous and skittish after Gortsby outed him. He does not seem to have had much experience in his profession. His success with Gortsby will undoubtedly encourage him to try his hard-luck story again. But he will be sure to have a cake of soap in his pocket--and he doesn't even have to buy one because Gortsby made him a gift of the soap he had found by the park bench.
The con-man can't claim that he hadn't bought the soap when Gortsby exposes the flaw in his story, because he had already explained why he is nearly flat broke.
"Of course I can wire to my people for the address, but they won't have got my letter till to-morrow; meantime I'm without any money, came out with about a shilling on me, which went in buying the soap and getting the drink, and here I am, wandering about with twopence in my pocket and nowhere to go for the night."