The reunion of Gatsby and Daisy is the novel's pivotal event; it sets all the subsequent events into inevitable motion. In Chapter VII, the story of their romance reaches its climax and its tragic conclusion.
Gatsby is profoundly changed by his reunion with Daisy: he ceases to throw his lavish parties and, for the first time, shows concern for his public reputation. In the past, Gatsby has simply ignored the vicious rumors circulating about him; for Daisy's sake, however, he must now exercise some discretion.
Daisy, by contrast, is extremely indiscreet with regard to her romance with Gatsby. Inviting Gatsby to lunch with her husband would be a bold, foolish move under any circumstances. When one takes Tom's snobbery and intense suspiciousness into account, Daisy's decision seems to border on madness. Tom is profoundly insecure, obsessed with both his own inevitable downfall and the downfall of civilization itself. It is important to recognize that, for Tom, they are one and the same. He believes that, as a wealthy white male aristocrat, he is Western civilization's greatest achievement. This odious mindset is borne out by his choice of reading material, which views the end of the world and interracial marriage as being equally catastrophic.
The confrontation between Gatsby and Tom serves to reveal the major flaws and motivations of both characters. For Tom, the affair between Gatsby and Daisy is evidence of the decline of civilization; he seems less disturbed by his wife's infidelity than by the fact that she is involved with a man of an inferior social class. Tom's gross misogyny and hypocrisy assert themselves with a vengeance. He obviously does not regard his affair with the even lower-class Myrtle Wilson in the same apocalyptic light. As Nick remarks, Tom moves "from libertine to prig" when it suits his needs.
Tom uses the fact of Gatsby's criminal activity