All of Rinehart's detective novels were to follow the pattern set by The Circular Staircase. The initial crime is only the first in a series of violent events which strike the characters throughout the novel. Other elements introduced in this novel include the infamous "Had-I-But-Known" narrative technique, where the first person narrator laments that, based on hindsight, she would have acted very differently; the blending of romantic subplots with the main mystery story line; the use of humor; and the shifting of attention from the detective to the victims and villains involved in the crime.
Rinehart also borrows a number of gothic elements for The Circular Staircase. It is set in Sunnyside, a rambling old mansion on Long Island, full of hidden rooms, secret passages, and things that "go bump in the night." The name of the house is, of course, ironic. While its surface appearance is benign, its interior hides great evil. The novel also features a middle-of-the-night disinterment in a cemetery, another direct borrowing from the gothic tradition.
(The entire section is 170 words.)