Luggnagg is an island that possesses a unique group of inhabitants that claim to be immortal.
When Gulliver journeys to Luggnagg attempting to pose as a Dutchman, his ruse is discovered, and he is incarcerated. The Luggnaggian King sends for Gulliver, and we then learn about the King's many idiosyncrasies. He requires those who come before him to approach on their hands and knees and to lick the floor. When someone falls out of favor with the King, he applies poison the floor they are to lick. Gulliver follows the King's eccentric customs, and because he is willing to submit to the questions posed to him, Gulliver is invited to stay as a guest of the royal court for three months.
Gulliver hears about the Struldbruggs during his stay, a group of people in Luggnaggian society who are apparently immortal. Gulliver reacts at first with excitement and envy, as this power would allow a person plenty of time to amass great knowledge, and gain immense wealth. His fantasies are crush, however, when an interpreter proceeds to explain the reality of life as a Struldbrugg. When Gulliver realizes that they still continue to grow old, feeble, decaying, and forgetful, his desire for this life of immortality disappears as quickly as it had formed.