Russell wrote many similar books, under various aliases, all in the faux autobiographical style of Vidocquian reminiscences, and inspired many imitators.

Amongst them are The Female Detective by Andrew Forrester, Jr, and Revelations of a Lady Detective, published anonymously but attributed to either Bracebridge Hemyng (1841–1901) or William Stephens Hayward (1835–1870). Both were published in 1864. The Female Detective features Mrs Gladden, usually known simply as ‘G’, who is a genuine consulting detective. Mrs Paschal of Revelations of a Lady Detective, on the other hand, is employed by the London Police Force in order to undertake undercover work. Between them they put the female detective firmly on the literary map.

Another nominee for the first female detective is Ruth Trail in Ruth the Betrayer; or, The Female Spy, by Edward Ellis, a penny dreadful which appeared in 52 weekly parts starting on 8 February 1862. Ruth isn’t really a detective. She’s an undercover agent who works on both sides of the law and, as the story develops, is more villain than heroine.

These and similar books such as Mary E. Braddon’s Three Times Dead; or, The Secret of the Heath (1860), also known as The Trail of the Serpent, are works which involve crimes and include some detection, but are in no way detective novels. But they do show a rapidly growing interest by the public in the work of the police, primarily for the more sensational and gruesome activities.

Many believe that the true father of the detective novel was the French writer Émile Gaboriau (1832–1873). Directly in the tradition of Vidocq, but further influenced by Poe, Gaboriau created the police detective Monsieur Lecoq in a series of five novels. In the first, L’Affaire Lerouge, he takes a back seat to the retired pawnbroker and consulting detective Father Tabaret, whose deductive skills Lecoq learns and adopts, but in the later novels Lecoq takes centre stage. L’Affaire Lerouge was first serialised in the daily newspaper Le Pays during 1863, after the magazine appearance of The Notting Hill Mystery, but our dates are closing in.

Before he became a full-time novelist, Gaboriau served as secretary to the author Paul Féval (1816–1875), a popular writer of crime thrillers and historical novels who developed a long series of linked novels involving international crime syndicates and conspiracies. Of special interest is Jean Diable, published in book-form in France in 1863 though not translated into English till 2004. It was serialised in Le Siècle from 1 August to 20 November 1862, concluding just a week before The Notting Hill Mystery began. Set in 1816, Jean Diable features the Scotland Yard detective Gregory Temple (even though Scotland Yard was not established until 1829). Temple has a painstaking, methodical and analytical approach to detection. The serial, long and rambling like most newspaper feuilletons of the day, involves Temple’s attempts to convict a master criminal. To French readers, the master criminal was more the hero than the English detective and in the final episode Jean Diable eludes conviction even though Temple has at last found the one vital clue that proves his guilt. The novel is undoubtedly crime fiction and is a step forward from the casebook-style novels, focusing on the tussle between a police detective and a master criminal. It is arguably the first police-procedural novel, and is certainly the closest to a genuine detective novel yet published.

So what makes The Notting Hill Mystery different?—and it is, quite startlingly different. For a start the investigation is by an insurance agent, Ralph Henderson. The novel is his report, presenting all the evidence to prove, to his satisfaction, that Madame R** was murdered and how. His report includes statements from a host of witnesses, including police statements, all of which are meticulously analysed and methodically assessed. There are no sensational chases, no battles with criminals, no undercover work. In that sense the novel is remarkably modern in its presentation. It seems to grow in entirely new soil, with no relationship to previous casebook reminiscences.

There are precedents, but only short stories. Wilkie Collins had written ‘Who is the Thief?’ (Atlantic Monthly, April 1858), later incorporated into his novel The Queen of Hearts (1859) as ‘The Biter Bit’. It’s a fairly light-hearted story, telling, by a series of extracts from police memoranda, how the villain was identified. In ‘Hunted Down’ (New York Ledger, 20 August–3 September 1859), Charles Dickens tells of a girl whose life is insured and who then mysteriously dies. Mr.