Question: What genre, usually involving a mysterious death, is exhibited by a book who features detective Sir Henry Merrivale?

Context paragraphs:
The Reader is Warned: The Reader is Warned is a mystery novel by the American writer John Dickson Carr (1906–1977), who published it under the name of Carter Dickson.  It is a whodunit and features the series detective Sir Henry Merrivale.

He Wouldn't Kill Patience: He Wouldn't Kill Patience is a mystery novel by the American writer John Dickson Carr (1906–1977), who published it under the name of Carter Dickson.  It is a locked room mystery and features the series detective Sir Henry Merrivale and his long-time associate, Scotland Yard's Chief Inspector Humphrey Masters.

Mystery fiction: Mystery fiction is a genre of fiction usually involving a mysterious death or a crime to be solved.  In a closed circle of suspects, each suspect must have a credible motive and a reasonable opportunity for committing the crime.  The central character must be a detective who eventually solves the mystery by logical deduction from facts fairly presented to the reader.  Sometimes mystery books are nonfictional.  "Mystery fiction" can be detective stories in which the emphasis is on the puzzle or suspense element and its logical solution such as a whodunit.  Mystery fiction can be contrasted with hardboiled detective stories, which focus on action and gritty realism.

Night at the Mocking Widow: Night at the Mocking Widow is a mystery novel by the American writer John Dickson Carr (1906–1977), who published it under the name of Carter Dickson .  It is a whodunnit and features the series detective Sir Henry Merrivale.

Murder in the Submarine Zone: Murder in the Submarine Zone (also published as "Nine—And Death Makes Ten" and "Murder in the Atlantic") is a mystery novel by the American writer John Dickson Carr (1906–1977), who published it under the name of Carter Dickson.  It is a whodunnit and features the series detective Sir Henry Merrivale.

And So to Murder: And So to Murder is a mystery novel by the American writer John Dickson Carr (1906–1977), who published it under the name of Carter Dickson.  It is a whodunnit and features the series detective Sir Henry Merrivale and Scotland Yard Chief Inspector Humphrey Masters.

The Gilded Man: The Gilded Man (also published as "Death and the Gilded Man") is a mystery novel by the American writer John Dickson Carr (1906–1977), who published it under the name of Carter Dickson.  It is a whodunnit and features the series detective Sir Henry Merrivale.

The Curse of the Bronze Lamp: The Curse of the Bronze Lamp (also published as "Lord of the Sorcerers") is a mystery novel by the American writer John Dickson Carr (1906–1977), who published it under the name of Carter Dickson.  It is a locked room mystery or, more properly, a subset of that category known as an "impossible crime", and features the series detective Sir Henry Merrivale.  Carr considered this one of his best impossible crime novels.

My Late Wives: My Late Wives is a mystery novel by the American writer John Dickson Carr (1906–1977), who published it under the name of Carter Dickson.  It is a whodunnit and features the series detective Sir Henry Merrivale and his long-time associate, Scotland Yard's Chief Inspector Humphrey Masters.

Death in Five Boxes: Death in Five Boxes is a mystery novel by the American writer John Dickson Carr (1906–1977), who published it under the name of Carter Dickson.  It is a whodunnit and features the series detective Sir Henry Merrivale and his associate, Scotland Yard's Chief Inspector Humphrey Masters.

Supporting paragraphs: Night at the Mocking Widow Mystery fiction
Answer: Mystery fiction