At the end of the story, after the banker has learned an important life lesson from the lawyer about the meaninglessness of material wealth (and seemingly grown emotionally), he immediately reverts to his morally corrupt ways—an example of situational irony. The irony comes across in the final lines of the story:
Never at any other time, not even after his terrible losses on the Exchange, had he felt such contempt for himself as now. Coming home, he lay down on his bed, but agitation and tears kept him long from sleep...
The next morning the poor watchman came running to him and told him that they had seen the man who lived in the wing climbing through the window into the garden […]. To avoid unnecessary rumours he took the paper with the renunciation from the table and, on his return, locked it in his safe.
After the banker reads the lawyer’s note and learns that the lawyer will leave his imprisonment five minutes before his 15 years are up because money is not important to him, the banker lies down in his bed and feels “contempt for himself” while experiencing “agitation and tears”—this is how readers know that he has been emotionally moved by the lawyer’s decision. He cries over the fact that he was willing to kill the lawyer to stop him from winning the bet while the lawyer was already going to leave early anyway because money is of no value to him.
The irony emerges when, the next morning, after a night of tears and self-reflection, the banker takes the note the lawyer wrote and “lock[s] it in his safe” in order to “avoid unnecessary rumours.” Here, the banker is back to his morally corrupt ways. He has locked away this document that actually made him feel something in order to maintain appearances and make it look like he won the bet.
Chekhov’s decision to end the story in this way communicates how hard it is for people to develop morally when the material realities of living in a society dictate that they prioritize socioeconomic stability over all else. That the lawyer—the idealist in this story—flees from society furthers this point.
In an example of situational irony, the lawyer decides to end his 15-year imprisonment just five minutes early, forfeiting the two million rubles he would have earned from winning the bet. The irony comes across in both the lawyer’s note to the banker where he reveals his decision and in the banker’s response, as seen in the following passage (which opens with an excerpt from the lawyer’s letter):
“That I may show you in deed my contempt for that by which you live, I waive the two millions of which I once dreamed as of paradise, and which I now despise. That I may deprive myself of my right to them, I shall come out from here five minutes before the stipulated term, and thus shall violate the agreement.”
When he had read, the banker put the sheet on the table, kissed the head of the strange man, and began to weep.
The lawyer makes it clear in his letter to the banker that this ironic twist is intentional: he is trying to teach the banker a lesson about the meaninglessness of wealth. Rather than laughing at the irony of the lawyer’s decision—or celebrating it—the banker “kissed the head of the strange man, and began to weep.” This response is ironic because, before reading this letter, the banker was so motivated by maintaining his wealth that he was planning to kill the banker. Therefore, readers would expect him to be thrilled by the lawyer’s choice. Instead, the banker weeps—not necessarily from happiness, but because the lawyer’s lack of interest in material wealth moves him and because he understands (even if momentarily) that money is perhaps not as important as he has always considered it to be.
