In Chapter Two of The Great Gatsby, Nick gets dragged into a dismal party at the New York apartment which Tom Buchanan keeps for his meetings with Myrtle Wilson. Myrtle's sister Catherine and a some nondescript neighbors are present. At one point Nick says:
The bottle of whiskey--a second one--was now in constant demand by all present, excepting Catherine, who "felt just as good on nothing at all." Tom rang for the janitor and sent him for some celebrated sandwiches, which were a complete supper in themselves. I wanted to get out and walk eastward toward the Park through the soft twilight, but each time I tried to go I became entangled in some wild, strident argument which pulled me back, as if with ropes, into my chair.
The whiskey brings out the hidden aspects of people's characters. Tom is a vicious brute. Myrtle is cheap and vulgar. She would like very much for Tom to divorce Daisy and marry her, which, of course, would mean that she would have to divorce her husband George. Tom and Myrtle are birds of a feather, but Tom is only looking for a casual affair and has no intention of leaving Daisy. At one point tempers flare, fueled by the bootleg booze:
Some time toward midnight Tom Buchanan and Mrs. Wilson stood face to face, discussing in impassioned voices whether Mrs. Wilson had any right to mention Daisy's name.
"Daisy! Daisy! Daisy!" shouted Mrs. Wilson. "I'll say it whenever I want to! Daisy! Dai--"
Making a short deft movement, Tom Buchanan broke her nose with his open hand.
This scene may be a better picture of the Prohibition Era than Gatsby's big parties.
The violence pretty much brings the party to an end. Myrtle is left there, being administered to by her sister. Myrtle will get back home on the train. She will have to explain her broken nose to her husband as best she can--but George is becoming very suspicious of these visits to her sister in New York, and his suspicions will lead to disaster. He will try to keep his wife locked in a room above the garage. She will go running out to talk to Gatsby when she sees him passing in his roadster and will get killed by Daisy, who is driving.
Fitzgerald uses the party and the incident between Tom and Myrtle for several purposes. He characterizes Tom as an uncouth lout in spite of his millions and his social status. He implies that Tom is unworthy of Daisy and that, consequently, Gatsby is justified in his quest to win her away from her husband. Fitzgerald is chronicling Prohibition and the Roaring Twenties, and with this sordid party he is depicting the darker side of the Jazz Era. Most of the drinking was not done at glamorous parties like those at the home of Jay Gatsby, but in humble homes with the radio playing. Booze made some people talkative, others sleepy, others sad, others violent--just as it still does today. Fitzgerald uses the characters present to display the varying effects of alcohol. It makes Nick want "to get out and walk eastward toward the Park through the soft twilight." He will remember this party for a long time. It is the first stage in his disillusionment with the East. At the end of the novel he writes:
After Gatsby's death the East was haunted for me like that, distorted beyond my eyes' power of correction. So when the blue smoke of brittle leaves was in the air and the wind blew the wet laundry stiff on the line I decided to come back home.
Fitzgerald had a love-hate relationship with liquor. It ended up destroying his talent and his life.