What do the two wealthy gentlemen offer Henry?

The two wealthy English gentlemen have a bet of twenty-thousand pounds which the narrator explains as follows:

Well, the brothers, chatting along, happened to get to wondering what might be the fate of a perfectly honest and intelligent stranger who should be turned adrift in London without a friend, and with no money but that million-pound bank-note, and no way to account for his being in possession of it. Brother A said he would starve to death; Brother B said he wouldn't. Brother A said he couldn't offer it at a bank or anywhere else, because he would be arrested on the spot. So they went on disputing till Brother B said he would bet twenty thousand pounds that the man would live thirty days, anyway, on that million, and keep out of jail, too. Brother A took him up.

They take a long time to select the man to whom they will entrust the million-pound bank-note. Finally they choose the narrator, whose name is Henry Adams, because he looks intelligent and trustworthy, even though he is penniless and nearly starving to death. Henry really is a trustworthy man. When he finds that they have apparently given him a million-pound bank-note by mistake, he goes back to their offices and tries to return it. But he is told they will be out of town for a month, and he is given a letter from one of the two brothers which reads as follows:

"You are an intelligent and honest man, as one may see by your face. We conceive you to be poor and a stranger. Enclosed you will find a sum of money. It is lent to you for thirty days, without interest....I have a bet on you. If I win it you shall have any situation that is in my gift - any, that is, that you shall be able to prove yourself familiar with and competent to fill."

Mark Twain manages to make this preposterous premise credible. Henry Adams has no money except for a bank-note worth a million pounds. He quickly finds out that the mere sight of it makes a staggering impression on anyone he offers it to as payment for some relatively trivial purchase. Nobody can cash such a bank-note, but everybody is more than willing to give Henry anything he wants on credit. At first he is taken for an eccentric millionaire because of his shabby clothing, but he soon changes his appearance by ordering a whole new wardrobe of tailor-made clothes, along with some ready-made clothes which had been left there by his Serene Highness the Hospodar of Halifax.

By the end of the story, Henry Adams has become a millionaire and is married to a beautiful girl who turns out to be the stepdaughter of one of the two fabulously wealthy brothers who initially entrusted him with the million-pound bank-note.

Mark Twain's premise has been copied innumerable times since the story was published in 1893. Brewster's Millions, for example, a novel by George Barr McCutcheon published in 1902, has been adapted into films ten times.