The primary theme of Alan Hollinghurst’s novel is the centrality of gay experience. Set in the turbulent 1980s in Thatcherite England, The Line of Beauty presents the theme of disease both in regard to the AIDS crisis and the political corruption that was contaminating society. Another, closely related theme is masks and disguise as people deliberately misrepresent their own identities and try to cover up inconvenient truths.

In three parts spaced several years apart, Hollinghurst focuses on the experiences of one gay man, Nick Guest. Nick, who is white, and his friends and lovers, represent gay experience as central, not peripheral, in society. Hollinghurst has written about his commitment to re-shaping ideas about narrative so that heterosexuality will no longer be assumed to be the norm. During these key phases in his life, Nick is involved in romantic and sexual relationships with several men, along with living as part of a community in which some people are out and others remain closeted. The characters of Leo and Wani show gay men of different races and ethnicities as experiencing and expressing their identities in relation to their families and cultures.

As time progresses, Nick becomes increasingly affected by the threat of AIDS as these friends and lovers fall ill. Disease is not only a reality that intrudes into all the characters’ lives but also serves as a metaphor for social malaise. Despite their knowledge of the ravages of HIV-related conditions, denial is equally prevalent. Discrimination against gay people in English society goes hand in hand with general unwillingness to admit that the disease affects everyone. Beyond any specific malady, however, the concepts of illness and contagion apply to the social problems, such as racism and poverty, that were quickly growing and spreading throughout society. This corruption has eaten away at politics, as exemplified by Gerald, Nick’s friend’s father, embroiled in a financial scandal.

Because of fear of persecution or rejection, many of the gay characters keep their true identity hidden. Rather than express themselves openly, they must disguise themselves in a cloak of heterosexual “normality.” For Leo, who is of African heritage, he fears alienation because of his mother’s Christian faith. Wani, an immigrant from Lebanon, hides his sexual orientation from his family. Another kind of mask is presented, however, in the rampant social and political corruption that the author explores. For example, the married Gerald criticizes Nick's relationship with Wani while involved in an affair with an employee.