Many of the most popular fictional detectives are somewhat eccentric – they need to be interesting if we are to carry on reading, but there are some outstandingly entertaining characters, often solving mysteries in rather unorthodox ways. It’s not enough for the detective to have a few quirks and foibles: they should be decidedly odd and the stories should also involve grotesque characters and bizarre goings-on, preferably in the alleys and back streets of London or in some kind of Gothic mansion – the legacy of Dickens maintains its grip. First, and best known, has to be Sherlock Holmes. Holmes was based on a real person, Joseph Bell, an Edinburgh surgeon. Holmes was sufficiently like Bell for Robert Louis Stevenson to identify the original in a letter to Sir Arthur Conan Doyle, complimenting him on:your very ingenious and very interesting adventures of Sherlock Holmes. That is the class of literature that I like when I have the toothache. As a matter of fact, it was a pleurisy I was enjoying when I took the volume up; and it will interest you as a medical man to know that the cure was for the moment effectual. Only the one thing troubles me: can this be my old friend Joe Bell? I am,Yours very truly Robert Louis Stevenson
(Letter dated 5 April 1893. Selected Letters, Edited Ernest Mehew 1997 p 540)Conan Doyle responded by confirming that Holmes was a cross between Bell and Edgar Allan Poe’s Monsieur Dupin (‘much diluted’).
We all recognise the meerschaum pipe, the violin-playing, the cocaine habit (which may not have shocked a Victorian audience as much as it does today’s readers) though several of Holmes’s best known characteristics, are later accretions: the deerstalker was first shown in one of Sydney Paget’s illustrations for The Strand magazine. His knowledge of certain everyday subjects is minimal while in other, more arcane areas he is an expert. However, he undoubtedly possesses an amazing forensic ability combined with acute powers of deduction – his ability to analyse his visitors’ background and habits surprises them and entertains us. The mysteries are splendidly macabre: The Adventure of the Dancing Men, The Adventure of the Speckled Band, The Red-headed League, The Five Orange Pips (1891-1904), The Sign of Four (1890), The Hound of the Baskervilles (1901-2).
A foil is usually necessary to display the eccentric one’s genius. Holmes has Dr Watson and the less than brilliant Inspector Lestrade: Margery Allingham gives Albert Campion the patient, though by no means stupid policeman, Stanislaus Oates, as well as Magersfontein Lugg, a criminal-turned-gentleman’s gentleman, who provides a comic, cockney Chorus. Albert Campion is a man of mystery, a member of a European royal family who finds it convenient to hide behind a large pair of spectacles and a mask of near-imbecility when assisting the police, the Government or his aristocratic acquaintances. Again, the mysteries are peculiar: the plot of Lookto the Lady (1931) involves a centuries-old Chalice and an ancient, terrifying ritual, witches, gypsies and a village full of strange characters. Police at the Funeral (1931) takes us to a mausoleum of a house in Cambridge where Caroline Faraday rules her very odd family with a firm hand – but then murder strikes twice. Allingham’s most famous novel is The Tiger in the Smoke (1952) which has plenty of London fog and a sinister villain to delight the reader.
Gervase Fen, the creation of Edmund Crispin (pen-name of composer Robert Bruce Montgomery), is an Oxford don, brilliant, vain, rude and fond of quoting Lewis Carroll. The plots are baroque and high-spirited, the writing is splendidly literary. How many modern crime authors would dare to write like this?:
When one came down to facts, Geoffrey was forced to admit, the notorious antisepsis of daylight seemed somehow lacking in effect. Nothing, essentially, had changed since the previous night; the events of yesterday, which, it was evident, the mind was only too willing to write off as perfervid delusions of its own, stood dismayingly impervious to such high-handed attempts at erasure…..
The New York Times called Crispin ‘the heir to John Dickson Carr….. and Grouch Marx’. 9 novels and a collection of short stories featuring Gervase Fen were published between 1944 and 1979 (the author had a serious drink problem and his output was erratic).
A worthy, modern successor to these writers is Christopher Fowler. His Bryant and May novels feature a pair of splendidly unconventional detectives who work for London’s Peculiar Crimes Unit. Their work takes them into hidden parts of the capital; its lost or forgotten buildings, underground rivers and empty theatres. Foggy, damp and enigmatic, London is viewed from odd angles and presented in unfamiliar aspects. Plots are gripping, often dealing obliquely with contemporary issues while the elderly detectives are cranky, awkward and brilliantly comic. They are surrounded by a faithful crew of associates including a cat, Crippen. These books are unusual and very funny. Full Dark House (2003) and The Water Room (2004) begin the series – 2011 saw the publication in hardback of The Memory of Blood – the paperback is due in 2012, as is the hardback of The Invisible Code. Have a look at Christopher Fowler’s own entertaining blog: www.christopherfowler.co.uk/blog.
Whilbert Stroop appears in the historical/detective/fantasy novels of Clio Gray. A Missing Persons Finder and compulsive list-maker with an encyclopaedic memory and a warm heart, Stroop, with his strange little band of 
adopted assistants, becomes involved in labyrinthine and frequently gruesome plots, ranging far across early nineteenth-century England and Europe.
The first book is Guardian of the Lost Key (2006). Stroop is drawn into a conspiracy involving the prosperous Italian silk community in London, Napoleon’s army and the ancient walled city of Lucca in Tuscany.
In Envoy of the Black Pine (2008): Stroop’s investigation leads him from a flooded valley in the Cotswolds and a sinister printworks, to the strange island archipelago of Saaremaa in the Baltic. Increasingly tangled strands of past and present reveal a mysterious world of ancient brotherhoods, insurrection, piracy, and death. The latest in the series The Brotherhood of Five (2009) appeared in paperback in March 2010.
Told with a wonderful eye for detail (often gory), superb characterisation and great imaginative power, these books really defy categorisation, but Stroop is most definitely a welcome addition to the select band of Eccentric Detectives.