[Jaruzel]

It also has to be said, that Christie created the 'reveal monologue' where the detective gets everyone in a room, and then dissects the murder and clues until the killer is unmasked. Without her, all crime writers that came later would write very different stories.

[lqet]

In Dostoyevski Crime and Punishment, there is a similar 'reveal' monologue with an extremely interesting twist (spoiler alert): the narrator knows the murderer, the reader knows the murderer, the detective knows the murderer, the reader knows that the detective knows the murderer - but the murderer, a naive student who is convinced he is the Übermensch and committed a perfect crime, is unaware that everyone knows he did it. It's both an extremely tragic and extremely funny scene: at one point they have a lengthy conversation where both of them "try" to find out who the real murder is, and the student, thinking he is helping the dumb detective with his superior mind, suggests one murderer after the other, one theory after another. The detective dismisses them all. Finally, the student grows frustrated and blurts out: "Then who is the murderer?". And the detective just answers: "The murderer? Why, you are, of course!". The silence that follows is one of the best moments in literature and a testament to Dostoyevski's genius regarding character development.

Of course, as many people know, that scene and in particular that seemingly clueless but extremely clever 19th century St. Petersburg detective inspired the Columbo series, which repeated this particular kind of "reveal dialogue" in basically every episode.

[majormajor]

My recollection is that the murderer there isn't really convinced he committed a perfect crime but frequently is panicked and pushed to extremes by suspicion that he's being toyed with (and in particular, the detective was intentionally making him ride a roller coaster of more or less suspicion of this)?

[rrauenza]

I wonder how much Colombo is influenced by this. I always thought of Columba as an upside mystery... everyone knows who did it, you just don’t know how it will get proven.

[ldjb]

Interestingly, in the case of And Then There Were None, the novel was originally published without its solution.

Christine's intention was that the reader would use the clues scattered throughout the book to work out who the culprit was. Indeed, like many other works from the Golden Age of Detective Fiction, the mystery is entirely solvable from those clues.

Christie ultimately added an epilogue to subsequent editions, which explains the mystery. In a sense, it's nice to have confirmation of what the solution is, but at the same time I like the idea that a mystery story doesn't necessarily need to include a solution.