The Ten Commandments of Mystery Writing Quiz

Answer: His inner thoughts

Introducing the murderer early in the novel (usually within the first quarter of the book at least) is essential because Knox believed the reader must have a fair opportunity to guess the killer's identity. The reader is not likely to suspect someone who only debuts late into the story. In addition, the reader cannot know the murderer's inner thoughts because those thoughts might reveal too much about the killer's ideas and strongly hint at their identity. The writer also cannot lie about what the killer is thinking because that would provide a false narrative to the story.

Most mystery novelists are very faithful to this commandment. However, it is not uncommon in the grittier or more hard-boiled stories to have the main culprit be someone introduced later in the novel if at all prior to their reveal as the killer.

Answer: They must be explained away by facts.

Supernatural happenings such as ghosts and strange disappearances must be solved by the detective. For example, if in a story a house is allegedly haunted, the mysterious happenings must be explained using coherent facts by the end of the novel. In addition, any murders cannot be caused by divine intervention, ghosts, vampires or any supernatural being. The solution must be earthly.

The appearance of a "ghost" or other supernatural being is a very common trope in detective stories. Arthur Conan Doyle's "Hound of the Baskervilles" and Gideon Fell's "He Who Whispers" both make use of fake supernatural events that have perfectly logical explanations.

Answer: One

Secret passageways are allowed in mystery stories but, according to Knox, only one can appear per story. The reason for this is that secret passageways are often overused in detective stories. They also give the writer an easy way to explain a character's movements or disappearance. Knox believed there were much more creative ways to handle these things and found that, in real life, secret passageways were quite rare. Oftentimes, the (rumored) existence of a secret passageway serves as a red herring, as in "They Do It With Mirrors" by Agatha Christie.

Answer: Fictional poisons

Knox firmly believed that any murder weapon used in a mystery novel must be something the average person should have a basic understanding of. Fictional poisons were one of the things Knox believed should not be allowed because the reader could not possibly have a basic understanding of the poison in question since it is not real. In addition, Knox also forbid the use of any weapon or method that could only be explained using complex scientific explanations.

Many writers remain faithful to this commandment but will play around with it. For instance, the weapon may be a real poison or something that does not require a complex scientific lesson. However, the way it was used might be overly complicated or require more explanation.

Answer: Chinese

Racial stereotypes were frequent in detective novels from the Golden Age. In particular, so-called "Chinamen" stereotypes were popular. Any person who was not white, Christian and British (in British set novels) or American (in American set novels) was often portrayed negatively and suspiciously, though they rarely turned out to be the culprit. Knox believed "Chinamen" specifically should not be allowed in detective novels because they were always portrayed in an offensive manner which ruined the story for him.

A prime example of the offensive stereotype is the detective Charlie Chan created by Earl Derr Biggers.

Answer: Accident

According to Knox, the detective must use his wits and methods of discovery to solve the crime. He cannot just accidentally stumble across the solution by some kind of accident outside his control without needing further thought on his part. In addition, the detective must explain his intuition and hunches. Oftentimes, detectives will do something unusual and seemingly for no reason that turns out to be the thing that solves the case. Such intuition must be explained by the detective and the detective just cannot claim to be so smart, he figured it out with ease.

This is one of the commandments that is frequently broken. It is very common for the detective to accidentally overhear a conversation or stumble across a piece of evidence by chance. Such is the case in many classic works of the genre, such as "Lord Edgeware Dies" by Agatha Christie.

Answer: The detective

Although some novelists have strayed from this commandment, Knox believed the detective should never be the murderer. The detective is the hero of the story and thus could never double as the evil murderer, since good must triumph over evil. In addition, having a detective investigating his own case could also lead to a dishonest narrative and unfairly deceiving the reader.

This is another commandment that is sometimes played with. However, the murderer is usually never the main detective in the story but another investigator. Knox considered all investigators off limits.

Answer: Reveal all the clues and information he finds

Since the reader must have a fair chance at solving the mystery, any and all clues must be presented to the reader. The detective is not allowed to hide any clues from the reader. In addition, once the detective has reached a conclusion (whether definitive or not) that must also be revealed to the reader. The reader needs to have access to the same information the detective has.

This commandment is directly mentioned in a few mystery novels and series. In the many Ellery Queen novels, there would be a point in the novel where the narration would stop and the author would inform the reader that he or she has all the information necessary to solve the crime. In the event information is withheld from the reader, the detective would tell the reader (via dialogue to another character) that the information withheld was not actually necessary to solve the murder. Hercule Poirot frequently did this to his right hand man Hastings.

Answer: Less intelligent than the reader

During the Golden Age, the detective's assistant was often the narrator. The sidekick is also bound by the same rules as the detective (such as not hiding clues and information). In addition, the detective's aide must not be smarter than the average reader. The assistant, too, is in the position of trying to solve the crime, and must not do so before either the reader does or before the solution is revealed by the detective. Knox believed the assistant should be just slightly less intelligent than the average reader so the reader can feel smart and stay one step ahead of the sidekick.

Dr. Watson, Captain Hastings and Inspector Queen are just a few of the "sidekicks" who appear to be of less than average intelligence in regards to crime solving. Each one would frequently fail to understand a piece of evidence, often misinterpreting it completely, leading them to suspect the entirely wrong person.

Answer: Secret twins

Knox felt that using twins, specifically twin brothers, as part of the solution was extremely unfair, cheap and uncreative. He did offer the exception that if twins were involved in the solution, the fact that there were twins must be announced well before the solution.

Almost every popular author from the Golden Age utilized twins or doubles in his or her novels at some point. These include "The Siamese Twin Mystery" by Ellery Queen and "Peril at End House" by Agatha Christie.