Anonymous Christie . . . or the Classic 12-Chapter Murder Mystery Formula

Adron J. Smitley
11 min readSep 5, 2020

No other genre in all of fiction requires more crafty planning and cunning editing backtracking than the murder mystery. Pantsing here doesn’t cut the story mustard, because you must plant clues both specious and genuine, lay false tracks, incorporate suspicious suspects and beguiling dialogue, inject red herrings, bait traps and spring logical though surprising plot twists throughout your story all with the devious ploy to keep the engaged reader guessing and second-guessing until the satisfying ending revealed to which the rejoicing reader declares, “Aha! Of course! I knew it all along!”

Sure you did.

And most of this crafty work flourishes from writing the entire story first then returning to page one and planting said clues and such with keen author hindsight during the first rewrite.

This specific ‘Classic 12-Chapter Murder Mystery Formula’ has been floating around the internet for years and then some. I’ve spent meticulous hours fondling Google’s naughty search engine to no avail as to retracing the proven plot formula to the original author for due credit. It’s been posted and reposted too many times for counting, and every place I’ve found it states the same disclaimer: they also have no idea who the original author is, though they’ve used it and/or know other writers who’ve used it to great success.

So I hereby officially dub the unknown author as “Anonymous Christie” after (obvious pun is obvious) best-selling murder mystery novelist Agatha Christie who is outsold only by the Bible and Shakespeare.

But before we delve into Anonymous Christie’s Classic 12-Chapter Murder Mystery Formula, let’s tickle our musing fancies with two other acclaimed mystery writers and their expert takes on the murder game.

Raymond Chandler’s 10 commandments for writing a detective novel:

1. It must be credibly motivated, both as to the original situation and the denouement.

2. It must be technically sound as to the methods of murder and detection.

3. It must be realistic in character, setting and atmosphere. It must be about real people in a real world.

4. It must have a sound story value apart from the mystery element: i.e., the investigation itself must be an adventure worth reading.

5. It must have enough essential simplicity to be explained easily when the time comes.

6. It must baffle a reasonably intelligent reader.

7. The solution must seem inevitable once revealed.

8. It must not try to do everything at once. If it is a puzzle story operating in a rather cool, reasonable atmosphere, it cannot also be a violent adventure or a passionate romance.

9. It must punish the criminal in one way or another, though not necessarily by operation of the law. If the detective fails to resolve the consequences of the crime, the story is an unresolved chord and leaves irritation behind it.

10. It must be honest with the reader.

*Raymond Chandler is considered the founder of the hard-boiled school of detective fiction. The protagonist of his novels, Philip Marlowe, is synonymous with ‘private detective’. At least three of Chandler’s novels are regarded as masterpieces: Farewell, My Lovely (1940), The Little Sister (1949), and The Long Goodbye (1953).

Frank Gruber’s Fool-proof 11-Point Formula for Mystery Short Stories:

“I (Frank) used to analyze stories. What elements were required? After a period of time I evolved a formula for mystery short stories. It consisted of eleven elements. With those eleven elements in a mystery plot, I could not miss. I used to work out each element at a time, concentrating on one until I had it licked, the going on to the next. Most writers of mysteries inject the eleven elements into their stories anyway, but by putting them down one at a time I became conscious of them. Once I had worked out these eleven elements, the job of coming up with plots for mystery stories was greatly simplified.

I did not create this 11-point formula at one time. I evolved it over a period of about two years beginning back in 1934. I had perfected it by about the middle of 1936.

To this day I claim that this plot formula is foolproof. You can write a perfectly salable mystery story with perhaps only seven or eight of these elements, but get them all into a story and you cannot miss. Here are the eleven elements:

— A hero must be colorful. He must have an occupation that is colorful or he must be a colorful person. In general, I have followed the theory that a regular policeman or detective is not colorful. Just think a moment about the greatest detective in all detective fiction — Sherlock Holmes — and you will quickly grasp what I mean by colorful.

— This, to me, is the most important element of any mystery story plot. By theme I mean subject matter, what the story is about in addition to, over and above, the ACTUAL MURDER plot.

To illustrate: “Death and the Main” is about fighting cocks. I give a reasonably inside account of how gamecocks are raised, how they are fought, etc. This is knowledge not possessed by the average reader and believe me, I did not know it until I read up on the subject, for the purpose of this story.

My book, The Lock & the Key, was about locksmiths. A liberal education in making locks and keys was thrown into the murder plot. I knew absolutely nothing about locks and keys until I did research on the subject. I know no more than is in the book.

If you have ever read Dorothy Sayers’ excellent English mysteries, you will find that THEME figures superbly. In The Nine Tailors, the reader earns all about church bells, the art of bell-ringing, etc. In Murder Must Advertise, Miss Sayres discusses advertising in all its phases.

However . . . knowledge of a subject should be used sparingly. The mystery reader may not be as interested in the subject as you are.

— Let’s face it, the hero of detective fiction is a Superman. The villain must therefore be a super-Superman or have plenty of assistants. The odds must ALWAYS be against the hero.

— The story must be played against a colorful or unusual background. The streets of a big city are not necessarily colorful. If they’re not, make them so.

— Here again, the “unusual” should be considered. Shooting, stabbing, etc. are acceptable, but the circumstances surrounding them should be “unusual.”

— Actually, there are only two reasons for murder — hate and greed, but there are many subdivisions of these and the motive should be as unusual as possible.

— Somewhere in the story there must be a clue for the alert reader. Sure, try to fool the reader, but the clue must be there if the reader should want to check back on you after the story is over.

— In the grand finale, when all seems lost, when the hero cannot possibly win out, he must snatch victory from apparent defeat. By a trick . . . and here the word “unusual” applies.

— The story must have pace and movement. It must not consist of talk, talk, talk, about the missing button, etc.

— A grand, smashing climax is necessary. Unusual.

— The hero should be personally involved in some manner. He should be doing this over and beyond the simple call of duty, or beyond the money paid him for doing it.”

*Frank Gruber sold over 300 stories to the pulps, as well penned his name to over 60 novels and over 200 television and film scripts.

The classic murder mystery is popular fiction which follows a specific formula for good reason — because it works!

Here below, Anonymous Christie’s 12-Chapter Murder Mystery Formula serves both the classic and modern mystery novel.

A typical story contains 60,000 to 65,000 words and is divided into 12 chapters like so:


-Chapter 1-

A. Disclose the crime and mystery to be solved. The crime must capture the imagination. It should be committed in an extraordinary way and either the victim, the perpetrator, or both, must be unusual. Provide the reader enough information about the victim to make them truly care that the perpetrator is found and justice served.

B. Early in the story, reveal clues suggesting both physical and psychological aspects of the initial crime. These clues should point to suspects and motive which will carry the sleuth (protagonist) to the end of Act 1. Some clues should point the sleuth in the right direction, others not so obvious, or recognized as factual clues until later in the story.

C. Introduce the sleuth who will solve the crime early, and have him or her do or say something clever or unexpected to establish them as unique. Create this sleuth character with care, and with an engaging personality to sustain the reader’s interest to the last page (or throughout an entire series of books). It is not necessary to disclose all aspects of the sleuth’s personality at the onset. Allow the description to unfold gradually while sustaining reader interest. Reveal enough background so the reader understands the world in which the sleuth functions (Small town sheriff, Scotland Yard detective, Pinkerton agent in the old West, country squire, investigative reporter in New York City, etc . . .).

D. Ground the reader in the time and place where the crime occurs. It is often useful to include some sort of symbol, an object or a person, in the opening scene which serves as a metaphor for what occurs in the story. The reappearance of this symbol throughout and especially at the conclusion of the story creates a certain organic unity; pepper it in, but not so much as to make it flagrant. Subtly works best.

E. Begin with a dramatic event. Some writers offer a prologue describing the execution of the crime in detail, as it occurs, possible from the point of view of the victim or perpetrator. The same information could also be revealed by a character through dialogue. Furnish sufficient details to allow the reader to experience the event as though he or she were actually there as witness. Another good opening is to place the sleuth in a dire situation and allow choice details of the crime to unfold in due course.

-Chapter 2-

A. Set the sleuth on the path toward solving the murder mystery. Offer plausible suspects, all of whom appear to possess logical motives, means and opportunity to commit the unique crime. Select the most likely suspects and have the sleuth question them. One of these suspects will turn out to be the actual perpetrator.

B. At the approximate mid-point of Act 1, something occurs which clarifies to the reader the crime is more complicated than originally thought. Provide hints so the reader can envision possibilities not yet known to the sleuth.

-Chapter 3-

A. Introduce the sub-plot. The main plot continues the progress of the story while the sub-plot carries the theme, which is a universal concept to which the reader identifies. Sub-plots tend to originate either in a crisis in the sleuth’s private life, or in the necessity of the sleuth to face a dilemma involving a matter of character, such as courage or honesty.

B. The ultimate resolution of the sub-plot demonstrates change or growth on the part of the sleuth, and will climax on a personal or professional level. That climax may coincide with, or occur as prelude to the climax of the main plot. The sub-plot may provide a vehicle for a romantic interest or a confrontation with personal demons of the sleuth. The author can manipulate the pace of the novel by moving back and forth between the main plot and sub-plot.


-Chapter 4-

A. Reveal facts about suspects through interrogations and the discovery of clues.

B. Flight, or disappearance of one or more suspects.

C. Develop a sense of urgency. Raise the stakes or make it evident that if the mystery is not solved soon then terrible consequences are unavoidable.

-Chapter 5-

A. Broaden the investigation to place suspicion on other characters.

B. Information gathered through interviews or the discovery of physical evidence should point toward the solution, although the relevance may not yet be apparent.

-Chapter 6-

A. Reveal the sleuth’s background while the sub-plot develops. Show the reader what drives them, what haunts or is missing in their life.

B. Establish the sleuth possesses a personal stake in the outcome, either because of threat to their life, or the possibility of revelation of matters deeply disturbing to them on an emotional level.


*This is the pivotal point in the story where it becomes evident that the sleuth hunted down the wrong track. Something unexpected occurs, such as the appearance of a second body, the death of a major suspect, or discovery of evidence which clears the most likely suspect. The story must take a new direction.

-Chapter 7-

A. Reveal hidden motives. Formerly secret relationships come to light, such as business arrangements, romantic involvements, unsettled scores or previously veiled kinships.

B. Develop and expose meanings of matters hinted at in Act 1 to slowly clarify the significance of earlier clues.

-Chapter 8-

A. The sleuth reveals the results of the investigation. The reader, as well the sleuth and other characters, are afforded an opportunity to review what is known and assess the possibilities.

B. The solution of the crime appears to be impossible. Attempts to solve the crime have stymied the sleuth. Misinterpretation of clues or mistaken conclusions have lead them in the wrong direction, and logic is applied to force a new way of grasping an understanding of the uncertainties.

-Chapter 9-

A. The sleuth reviews the case to determine where they went wrong.

B. Reveal the chain of events which provoked the crime.

C. The crucial evidence is something overlooked in Act 1, which appeared as of little consequence at the time of initial disclosure. This crucial evidence takes on new meaning with information disclosed in Act 3.

D. The sleuth (and perhaps the reader, if a keen observer) becomes aware of the error which remains undisclosed to the other characters.


-Chapter 10-

A. The sleuth weighs the evidence and information gleaned from the other characters.

B. Based on what only they now know, the sleuth seeks positive proof to reinforce the yet undisclosed conclusion.

-Chapter 11-

A. Resolution of the sub-plot.

B. The sleuth, tested by their private ordeal, is strengthened for the final action leading to the actual solution of the murder mystery.

-Chapter 12-

A. The climax; a dramatic confrontation between the sleuth and the perpetrator in which the sleuth prevails. The more impossible the odds, the more rewarding the climax.

B. Resolution; revelation of clues and the deductive process leading to the stunning solution. Establish that the case has been solved and justice served to the satisfaction of all involved (except, of course, the perpetrator).

Well there you have it, folks. Anonymous Christie’s 12-Chapter Murder Mystery Formula . . . and then some.

Happy writing!

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Adron J. Smitley

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