The Last Mystery of Edgar Allan Poe: The Troy Dossier true to the character and known history of Poe. The plot concerns an attempt to overthrow the United States government. The novel is one of the earliest to engage the historical Edgar Allan Poe as a protagonist in a detective novel. Poe is considered to be the inventor of the classic tropes of detective fiction with his character C. Auguste Dupin, so it is natural that writers would utilize him in their fictions, especially given the recent rise of the historical novel. Many other writers have done this, including Louis Bayard in "The Pale Blue Eye" and true crime writer
Dupin cyclide of Dupin cyclides is invariant under the larger group of all Lie sphere transformations; any two Dupin cyclides are Lie-equivalent. They form (in some sense) the simplest class of Lie-invariant surfaces after the spheres, and are therefore particularly significant in Lie sphere geometry. The definition also means that a Dupin cyclide is the envelope of the one-parameter family of spheres tangent to three given mutually tangent spheres. It follows that it is tangent to infinitely many Soddy's hexlet configurations of spheres. A further special property of a cyclide is: An elliptic cyclide can be represented parametrically by the following formulas