What would the lawyer gain by not leaving early?
As mentioned above, if the lawyer stayed in solitary confinement for the fifteen years stipulated in the bet, he would be given two million rubles by the banker. As it turns out, however, the lawyer chooses to leave before the alloted time, and so he forfeits all rights to any money whatsoever. The lawyer does this because the almost fifteen years of incarceration have taught him that money has no value to him any longer. He has learned deeper truths about life and material things, and so, in his mind, he would be gaining nothing by staying and collecting on his bet. This is part of what he writes to the banker before he leaves:
"To prove to you in action how I despise all that you live by, I renounce the two million of which I once dreamed as of paradise and which now I despise. To deprive myself of the right to the money I shall go out from here five hours before the time fixed, and so break the compact ..."
The lawyer would win the bet of two million rubles. He had made a bet with the banker fifteen years before when the two got into an argument over capital punishment. The lawyer felt life was worth living no matter what the circumstances, but the banker felt capital punishment was more humane. The bet was for the lawyer to live without human contact for fifteen years to prove his point.