Chapter three in The Great Gatsby, is the first time we meet Gatsby. He has thrown a lavish party and people just show up for it. Nick is the only one who has received an invitation, and this sets Nick apart from the other guests.
Nick is at the party and meets Jordan Baker, and the two strike up a friendship. They talk among the guests trying to find Gatsby. They hear wild stories about Gatsby. Nick strikes up a conversation with a man, not knowing that it is Gatsby, and we learn that Nick spent time in the war. In this chapter we also learn that Nick works in New York City. He has a love for the city. We see that he walks down fifth avenue and dreams of a relationship with some of the women he passes. We see a lonesomeness in Nick. At the advice of Daisy and Tom, Nick begins a relationship with Jordan, although he calls her dishonest. He knows this about her, yet still continues a relationship with her. Nick's description of Gatsby when he first meets him, shows us that Nick is enchanted with Gatsby, as many others are as well.
"He had one of those rare smiles with a quality of eternal reassurance in it, that you may come across four of five times in life. It faced, or seemed to face, the whole external world for an instant and then concentrated on you with an irresistible prejudice in your favor. It understood you just as far as you wanted to be understood, believed in you as you would like to be believed in yourself."
From this description, we can see the effect that Gatsby could have on a person. Nick felt an instant connection with Gatsby. It is also worth noting, that Nick was now moving away from his Midwestern values and concerns in order to take advantage of the excitement of his new surroundings and new circle of friends. The last line in this chapter, is telling of Nick, as well. He is talking about how Jordan was not trustworthy and he says "I am one of the few honest people he knows" this sets up the rest of the story for us.