The Mad Hatter Mystery, first published in 1933, is a detective story by John Dickson Carr

John Dickson Carr

John Dickson Carr was an American author of detective stories, who also published under the pen names Carter Dickson, Carr Dickson and Roger Fairbairn....

 featuring his series detective Gideon Fell

Gideon Fell

Doctor Gideon Fell is a fictional character created by John Dickson Carr. He is the protagonist of 23 novels from 1933 through 1967 as well as a few short stories. Carr was an American who lived most of his adult life in England; Dr. Fell is an Englishman who lives in the London suburbs.Dr...

. This novel

Novel

A novel is a book of long narrative in literary prose. The genre has historical roots both in the fields of the medieval and early modern romance and in the tradition of the novella. The latter supplied the present generic term in the late 18th century....

 is a mystery of the type known as a whodunnit.

Plot summary

A young newspaperman, Philip Driscoll, is gaining notoriety by writing up a series of bizarrely inconsequential crimes in which various hats are being stolen and returned in unlikely locations; he ascribes the crimes to "the Mad Hatter". Driscoll's uncle, Sir William Bitton, is infuriated to have lost two hats in three days. He meets with Gideon Fell to discuss his possession of the manuscript of an unpublished story by Edgar Allan Poe

Edgar Allan Poe

Edgar Allan Poe was an American author, poet, editor and literary critic, considered part of the American Romantic Movement. Best known for his tales of mystery and the macabre, Poe was one of the earliest American practitioners of the short story and is considered the inventor of the detective...

. During the meeting, it is learned that Philip Driscoll has been found murdered at the Tower of London

Tower of London

Her Majesty's Royal Palace and Fortress, more commonly known as the Tower of London, is a historic castle on the north bank of the River Thames in central London, England. It lies within the London Borough of Tower Hamlets, separated from the eastern edge of the City of London by the open space...

, with Sir William's oversized hat pushed down over his ears. After sorting out the comings and goings of Sir William's household and other visitors to the Tower, Gideon Fell must determine the fate of the manuscript and of the murderer.