"The Great Believers," the new novel by Rebecca Makkai, describes the AIDS epidemic in Chicago in the 1980s and its impact on the gay community. Whereas the story of the disease in the United States tends to be a New York or San Francisco tragedy, here it is a "slow-motion tsunami from both coasts," a pool of water collecting at Midwestern ankles that climbs so quietly many are surprised to find themselves drowning. The book begins in 1985 at a Lincoln Park memorial for a gay man whose family disowned him, only to reclaim him at the last moment, "insisting he die in the suburbs in an ill-equipped hospital with nice wallpaper"; it finds a city where initial survivors, not yet seeing the reach of AIDS, don't know whether to host rowdy house parties in honor of the dead or somber, hands-folded funeral services. It visits Door County, Wis., and the Art Institute of Chicago; it finds a place for World War I Europe circa 1918 and the secluded nooks of Belmont Harbor circa 1982 ("a gay space hidden from the city but wide open to the vast expanse of Lake Michigan"). It ends in Paris, several decades and many victims later.