Agatha Christie’s And Then There Were None is the best-selling mystery of all time. Why?
ATTWN is so popular because it speaks to so many different desires and needs of human beings; motivations so deep in the meaning of what it means to be human that the novel will be timeless.
Three of the more obvious motivations:
1. The need for justice: everyone wants the wicked to be punished. It speaks to a primary desire in us to be safe from those who would do us wrong. However, to punish the wicked in a way that is brutally satisfying requires the punisher to become wicked. ATTWN neatly solves this by saying that the wicked destroy the wicked, meaning that “crime never pays”, another deep-seated belief is acknowledged.
2. The need for recognition: everyone wants to be remembered. In ATTWN, the murderer holds onto this belief (he writes a confession in a bottle that he throws out to the sea before committing suicide). In this way,ATTWN shows how even the most twisted and distorted holds onto this desire. In this way, the reader is relieved of any guilt for having such a potentially-selfish desire because they are shown that it is natural for everyone to want this.
3. The need for superiority: everyone wants to feel good about themselves by comparison. The murderer wants this, the victims wanted this. ATTWN gives the reader what they want by letting them feel superior.
It doesn't really matter that this is fiction; it happens in real life.
In Agatha Christie’s And Then There Were None, setting plays an important role. The story takes place on Soldier Island, isolated from the rest of the world. The guests arrive by boat, but are stranded on U. N. Owen’s island.
The first important factor to note is how the island is set apart from the rest of the world; communication and transportation between Soldier Island and the rest of the world is impossible. In this way, the characters are stranded in a place cut off from any sense of society. Agatha Christie is displaying how society is artificial, and without it how people return to their essences. By keeping the characters away from anyone who could judge them, the murderer ensures that the character’s true nature is revealed.
Another important thing to note is the name of the island: Soldier Island; a subtle reminder to how morals are abandoned in a time of war, and how everything seems acceptable when in the heat of action.
A final detail to be noticed is the owner of the island: U. N. Owen, a pun on “Unknown”. Without a host present, and without knowing who the host is, it appears that there is no host or owner. The author is very clever in a sense that one can only know by reading this book!
Throughout the novel And Then There Were None by Agatha Christie, the characters evolve. Not that that's unusual in literature, this is just good because of how it ties to the themes of the novel.
Throughout the novel, the characters are killed off one by one, in order of what the murderer deems least guilty to most guilty. In this way, the most wicked people will survive the longest.
The murderer does not just want to kill those he/she believes is evil; he/she wants to send a message. Those who are the most evil are subjected to increasing levels of paranoia and hysteria. The murderer wants his/her victims to suffer.
In this way, the characters evolve. As they are picked off, fear creeps into their minds and takes over. This causes the characters to become more crazy, and more untrusting; this culminates in one of the “victims” murdering another “victim”. In this way, wickedness destroys itself (as the murderer believes that the “victims” are all evil). Also, emotions that are generally thought to bring out negative qualities in people (fear, panic, anger) are the emotions that the murderer believes will show the true nature of those exposed. In this way, the murderer confirms his/herself in believing that the true nature of the victims is wickedness, which wickedness will bring out, and which wickedness will destroy. Agatha Christie did one amazing job at showing this throughout the entire novel!
In the book And Then There Were None by Agatha Christie, the following poem appears to foreshadow the series of murders that occur throughout the novel:
Ten little Soldier boys went out to dine;
One choked his little self and then there were nine.
Nine little Soldier boys sat up very late;
One overslept himself and then there were eight.
Eight little Soldier boys traveling in Devon;
One said he'd stay there and then there were seven.
Seven little Soldier boys chopping up sticks;
One chopped himself in halves and then there were six.
Six little Soldier boys playing with a hive;
A bumblebee stung one and then there were five.
Five little Soldier boys going in for law;
One got in Chancery and then there were four.
Four little Soldier boys going out to sea;
A red herring swallowed one and then there were three.
Three little Soldier boys walking in the zoo;
A big bear hugged one and then there were two.
Two Little Soldier boys sitting in the sun;
One got frizzled up and then there was one.
One little Soldier boy left all alone;
He went out and hanged himself and then there were none.
This poem expresses three levels of irony.
1. It’s ironic that all the deaths are made to seem accidental, or self-inflicted. The child-like language and simple rhyming pattern adds to this. This seems ironic because it is obvious that the deaths will all be murders, against the wishes of the victims. It is implied that the murderer of these people believes that because they have done wrong, they have already condemned themselves. This obviousness disconnect between the murderer and the victims is realized by all, but the victims are hapless to stop the murders.
2. The meaning of how the victims were unable to stop being murdered is a metaphor for how the victims were also unable to stop themselves from killing: although they express regret and admit to their roles in the murders, none of the victims could help themselves. This is ironic because the murderer’s poem contradicts itself slightly, which is only known to the reader.
3. Finding irony in this novel. The murderer is confident, and attributes his/her murders to justice. It’s ironic then that justice (something that is crucial and serious) is the source of the black-humor in this book.
ATTWN is so popular because it speaks to so many different desires and needs of human beings; motivations so deep in the meaning of what it means to be human that the novel will be timeless. 
