She is the story of Cambridge professor Horace Holly and his ward Leo Vincey, and their journey to a lost kingdom in the African interior. The journey is triggered by a mysterious package left to Leo by his father, to be opened on his 25th birthday; the package contains an ancient shard of pottery and several documents, suggesting an ancient mystery about the Vincey family. Holly and Leo eventually arrive in eastern Africa where they encounter a primitive race of natives and a mysterious white queen, Ayesha, who reigns as the all-powerful "She" or "She-who-must-be-obeyed" and who has a mysterious connection to young Leo.

The story expresses numerous racial and evolutionary conceptions of the late Victorians, especially notions of degeneration and racial decline prominent during the fin de siècle. In the figure of She, the novel notably explored themes of female authority and feminine behaviour. It has received praise and criticism alike for its representation of womanhood.