Summarize what has happened to the banker while the lawyer has been in confinement.
The banker went financially and psychologically downhill during the years that the lawyer was in solitary confinement in a lodge on the banker's estate, but Chekhov does not maintain that there was a connection between the one and the other. Here is how Chekhov describes the banker's decline:
Fifteen years before, his millions had been beyond his reckoning; now he was afraid to ask himself which were greater, his debts or his assets. Desperate gambling on the Stock Exchange, wild speculation and the excitability which he could not get over even in advancing years, had by degrees led to the decline of his fortune and the proud, fearless, self-confident millionaire had become a banker of middling rank, trembling at every rise and fall in his investments.
It was necessary for Chekhov to create this decline in the banker's character and capital in order to make it clear why the two million rubles meant so much to him now. At one time. his millions had been beyond reckoning, but now he would have to sell his estate and liquidate all his assets in order to pay the lawyer the two million he had bet. The banker was obviously a reckless, extravagant sort of man, and he would have been in the same financial position even if he had never even met the lawyer. However, Chekhov uses the banker's fear and moral decline to illustrate just one of the bad things that can happen to men who place too much importance on material things. It is only a coincidence that the lawyer has been gradually learning to despise material things at the same time that they have become so important to the banker that now he is considering committing murder in order to cling to the remainder of his wealth. The banker might be considered an example of what the lawyer has learned about life during his fifteen years of seclusion and study.