A detective story usually opens with an introduction to the mystery that it hooks young readers. The setting is usually described as part of the hook, as well. The isolated community of three dozen Puritans in "The Glass Village," by Ellery Queen, or the elite British private school where a murder was committed in "Well-Schooled in Murder," by Elizabeth George, are both examples of memorable settings.
In a detective story, the detective is the protagonist and is usually not considered a suspect in the crime. Arthur Conan Doyle's Sherlock Holmes and Agatha Christie's Miss Marple are classic examples of protagonist detectives. The detective analyzes the crime and collects a series of clues, such as the discovery of a hair at the crime scene that isn't human, as in "The Murders in the Rue Morgue," by Edgar Allan Poe. The detective then proposes several suspects to track down, one of whom is the criminal. This aspect of reading a detective story can boost critical thinking and problem-solving skills, because it allows a student to work through the clues to make a hypothesis about who committed the crime.
It isn't always easy to solve a detective story before the end. Suspense, inference and red herrings make for a more entertaining read. Many detective stories don't outline each and every aspect of the crime, which means the reader must use inferences to fill in the blanks, according to Scholastic. Suspense is another characteristic of a detective story, an element evident in "Shutter Island," by Dennis Lehane. Red herrings are created to give readers false conclusions, which adds more suspense -- for example, in "The Hound of Baskervilles," by Arthur Conan Doyle.
A detective story works through a series of clues and ends with the detective solving the crime and usually bringing the perpetrator to justice. While some mysteries end with an unknown subject being the criminal, the convention is to conclude based on evidence provided in the book -- it's considered unfair to readers to surprise them with an ending or perpetrator not based on the clues.