In the beginning of the book they introduce Nick. He moved from the Midwest to New York to get rich by becoming a stock broker. His second cousin, Daisy, also lives in New York and is married to Tom Buchanan. Since Nick is liked by everyone he learns a lot. One of the first people he learns of is Gatsby, his next-door neighbor. Then he learns about Daisy and Gatsby's past relationship. They used to be a couple until they broke up because of the fact that Gatsby was away at war and had lost his money. So that basically made him not worth loving in Daisy's eyes. Finally, Nick learns about Tom's relationship with Myrtle which was currently going on behind Daisy's back. From that moment he hears about Gatsby and sees his house, he is envious and gets his opportunity to meet him at one of Gatsby's parties.
When Nick goes over to the party, he meets Gatsby and learns that he and Gatsby had fought together in the same division in World War I. After that first conversation they begin to build a friendship, and Nick begins to fits in.
So one day, he meets up with Jordan, and she tells him about Gatsby's previous relationship with Daisy. Jordan explains to Nick, that Gatsby is still deeply in love with Daisy and wishes to get back with her, but he kind of needs Nick's help. So then Nick invites Daisy and Gatsby over to his house, and they finally get to meet again. Daisy and Gatsby fall in love. Daisy is won over, strangely, by the number of shirts that Gatsby owns. Daisy starts hanging around with Gatsby, which makes Tom suspicious. Tom starts coming to Gatsby's parties with her. After one of the parties, Gatsby begins to realize that his relationship with Daisy isn't quite what it used to be. Before they used to sit and talk for hours says Gatsby. Gatsby dream is that Daisy will to go to Tom and say "I never loved you". Then they could go live happily ever after. He wishes that he could bring back the love they had for each other like before the war.
So one day, Tom and Daisy invite Gatsby, Nick, and Jordan Baker out to lunch at their house in New York. Daisy and Gatsby finally reveal their love in front of Tom. They then all go to town where Daisy and Gatsby act extremely in love which makes Tom extremely jealous. When they all went out for dinner, he accuses Gatsby of trying to start trouble in his house, and they start to fight. Daisy says that she loves Gatsby and that she doesn't love Tom anymore. Then Tom tells Daisy and Gatsby to leave. So then George Wilson and his wife, Myrtle, which is who Tom is having his affair with is also having an argument. So she runs out of the house, only to be hit by Gatsby's car, driven by Daisy, and is killed instantly. Tom comes by after the other car had left and saw that his lover was dead. Later on, Tom tells Wilson that Gatsby is to blame for his wife's death. Wilson then goes over to Gatsby's house and kills Gatsby, then shoots himself. Because Nick is Gatsby's friend, he makes the funeral arrangements. Then he tries to find some of Gatsby's other friends and quickly realizes that the few friends that Gatsby does have don't really care about him. So there was only three people that ended up gong too Gatsby's funeral. Very saddened by Gatsby's death, Nick ends up moving back to the Midwest to start a new life.