The Notting Hill Mystery is an English-language detective novel published in 1863, which crime writer Julian Symons and others called "the first detective novel," preceding Wilkie Collilns's The Moonstone by several years. However, as fellow blogger John Norris of Pretty Sinister Books noted, historian Brian Stableford has taken exception to that claim, stating that Jean Diable by Paul Féval, published as a serial in 1862, was actually the first detective novel (featuring the Scotland Yard detective Gregory Temple). Another novel by Mary Elizabeth Braddon, The Trail of the Serpent, published in 1861, could also make a good case for being the "first," but so could other works of fiction that had detectives in them (e.g. Charles Dickens' Bleak House from 1852). 

As to the author? Notting Hill also started out as an eight-part serial, with illustrations by George du Maurier, that ran in Once a Week magazine, but the author was listed as "anonymous." Paul Collins, writing in the New York Times Book Review, believes the author was actually Charles Warren Adams (1833-1903), a lawyer, author and publisher who wrote novels under a pseudonym, including a crime novel titled Velvet Lawns from 1964. Collins also pointed out that Adams was also notably religious, which is why the novel has strong moral undertones.

The story is set in London, where the wife of a myterious and sinister Baron R dies after allegedly sleepwalking into her husband's laboratory and drinking from a bottle of acid. Insurance investigator Ralph Henderson, working on behalf of several companies, is called into investigate. At first, it seems the Baron had no part in his wife's death, and is referred to by many as a good-hearted man and a loving husband. But Henderson soon learns the husband had taken out at least five life insurance policies on his wife. Henderson eventually comes to the conclusion that Baron R has committed not one but three crimes, but he can’t prove it.

The narration is written in seven sections—memoranda to his corporate bosses—as a series of maps, medical and chemical analysis reports, illustrations, eyewitness interviews, family letters and diary entries, all features that were groundbreaking in style. Henderson details them all, because the evidence is "not only circumstantial but so delicate and complicated that the failure of a single link would render the remainder worthless." Ultimately, the disposition of that evidence is left up to the reader as to whether they are enough to convict Baron R beyond reasonable doubt.
  
The reception of Notting Hill, and its tale of poisoning, hypnotists, gypsies, and kidnappers, was positive when it was first published: the Guardian called it "very ingeniously put together", the Evening Herald said "the book in its own line stands alone", and the London Review described it as "a carefully prepared chaos, in which the reader, as in the game called solitaire, is compelled to pick out his own way to the elucidation of the proposed puzzle."

After long being out of print, the British Library issued a new edition for the book's 150th anniversary that includes the original illustrations by du Maurier (the grandfather of author Daphne du Maurier), as well as an introduction by Mike Ashley.