In Tender Is The Night, Fitzgerald traces the lives of its three main characters: Dick and Nicole Diver, and Tommy Barban. Throughout the novel their tempers change, their lives turn to a different way and each one affects the other.
At the beginning of the novel, book 1 presents us a perfect Diver family. Dick and Nicole Diver seem to be happy as if they were meant to each other: the perfect couple. We meet a pleasant and charming Dick Diver who knows how to handle every situation and take control over it in a very agreeable way. The lived near French Riviera at Villa Diana and liked to have social gatherings and parties with their friends and tourists on the beach, restaurants and also at their house. People admired Dick and felt attracted to him because of his good temper, exquisiteness and good manners. He tries to make people feel happy, or at least pleased. For example, although he knew that McKiscos were some kind of annoying people, Dick invited them to a party in his house. He wanted to make them feel part of his group of friends. To make new friends was like a pleasant pastime for Dick.
In book 1 there is not much characterization about Nicole and Tommy Barban. Fitzgerald introduces her as the wife to Dick, but it is trough the eyes of Rosemary that we meet a beautiful woman in Nicole. Rosemary admired her because of her great beauty, fineness, and her ease to spend her money buying splendid gifts for her friends every time she went out for shopping. On the other hand, we learned about Tommy that he was a stockbroker, also a professional mercenary, and a good French friend to the Divers.
It is not until the incident Violet McKisco saw in the Diver's bathroom that we don't know there is something wrong with Nicole. This event pushed the duel between Albert McKisco and Tommy Barban who wanted to safe Nicole's reputation. This episode hints that Tommy loves Nicole and presages a future affair between them.
The presence of Rosemary affects the relationship between Dick and Nicole as wife and husband. Rosemary's youth and beauty take off Dick's attention to Nicole and draw it to her. The young actress fell in love with Dick and in a short time he succumbed. His control fell down, they kissed each other, and confessed to themselves their "love" or infatuation for each other. Although Dick started a moral decay with these acts of kissing Rosemary, he abstained from having sex with her at that time.
Once we get into book 2, we learn the real background of the Divers, behind that pleasant and leisure life they have on book 1. Dick was a psychiatrist who studied in Yale thanks to the fact that he had enlisted on the army. He was from common roots in America; different to Nicole who was a daughter to an American millionaire. His manners and enchantment had been learned from experience, not inherited from a high-class stratum. Nicole and Dick met at a psychiatric clinic in Zurich, where Dick was sent in the time of the World War...