Downsiders
Downsiders is an award-winning 1999 novel by Neal Shusterman.
The Downsiders which is located underneath New York City, is a secret community of an unknown population (either native-born or "fallers" from the topside) that are never allowed to travel to the Topside (the surface). Talon, a fourteen-year-old Downsider, is curious about the Topside; he travels to the Topside and meets a fourteen-year-old girl named Lindsay Matthias, who just moved to her father's NYC townhouse after her mother went to Africa with her professor for three years to study the white rhino. Things get off to a rocky beginning, but they become friends. However, when Talon brings Lindsay to the Downside, the Wise Advisors (the Downside's government) find out and sentence Talon to death by executing him in the pipe system. Talon survives; he winds up on Coney Island "under the boardwalk," and has the time of his life, experiencing the "strange Topside rituals" for the first time.