And Then There Were None: Genre 1 key example

In this novel, the stakes of the mystery rise as more and more characters are killed by the unknown murderer. As the characters attempt to identify the guilty party, the reader must also pay careful attention to clues in order to solve the mystery. Many of the conventions of the genre are exemplified in a scene in which Justice Wargrave, a retired criminal judge, explains their shared predicament to the party of guests on the island: 

“You have none of you yet grasped what a very peculiar situation this is. To my mind there is only one course of procedure to adopt. Is there any one whom we can definitely eliminate from suspicion on the evidence which is in our possession?” 

Cite this Quote

Dr. Armstrong said quickly: “I, am a well-known professional man. The mere idea that I can be suspected of—” 

Again a gesture of the judge’s hand arrested a speaker before he finished his speech. Mr. Justice Wargrave said in his small clear voice: “I too, am a well-known person! But, my dear sir, that proves less than nothing!" 

Most of the guests, including Dr. Armstrong, are socially respectable individuals who bristle against the accusation of murder. However, Justice Wargrave argues that any one of them might be the murderer, insisting that nobody is above suspicion. Because no character can be conclusively ruled out, the reader must carefully weigh the evidence against each of them.