More and more novelists who use Barcelona as their setting seem intent on transforming the city's sunny Technicolor into a murky monochrome. Manuel Vázquez Montalbán's crime fiction plays out on the Catalan capital's meaner streets, while Carlos Ruiz Zafón's 2001 bestseller, "The Shadow of the Wind," immersed the reader in its mysterious Cemetery of Forgotten Books. "Mediterranean Noir" doesn't sound as convincing as its northern counterpart, Nordic Noir, but as writers increase the body count, a term may soon have to be devised.

Marc Pastor, a real-life crime-scene investigator in Barcelona, is the latest author to focus on the city's underbelly. "Barcelona Shadows," his first book to be published in English (it was translated from the Catalan by Mara Faye Lethem), is part detective story, part Gothic horror, with echoes of Edgar Allan Poe, Robert Louis Stevenson and Sir Arthur Conan Doyle. His events unfold in Barcelona at the turn of the century. His dynamic lead, Inspector Moisès Corvo, is on the trail of a "monster" who is abducting prostitutes' children. Corvo's investigations take him to grubby bars and brothels, plus a glitzy casino and magic show; he encounters thieves, gypsies, a one-handed palm-reader, a Russian illusionist, a schizophrenic who believes he is Jesus and a sinister Austrian doctor obsessed with evil.

But the main pull is the wicked Enriqueta Martí Ripollès, a woman who strikes fear into all who cross her path. As she stalks the streets, she reinforces Pastor's description of Barcelona as a "city of masks and lies." From the novel's memorable opener, featuring grave robbers disinterring a headless corpse, to the denouement in which Corvo lies gagged and bound in a cockroach-infested apartment, it is clear that Pastor's city tour is one very much off the tourist-beaten track.

The best fictional detectives are those who stand out as different from the rest, whether through intriguing personalities or quirky habits, and Pastor impresses by rendering Corvo jaded and debauched. He drinks, beats suspects and enjoys the company of prostitutes. His wife sniffs his clothes, but, "Luckily for the detective, the smell of rotting corpse is so strong it drowns out the scent of shady intentions and sex for money."

Two faults — one minor, the other potentially major — are worth noting. First, by Anglicizing the many street names ("Ferran Street," not Calle Ferran) the otherwise excellent translator prevents us from completely surrendering ourselves to Pastor's world. (Poe's classic short story would undoubtedly have lost something if titled "The Murders in Morgue Street.") Second, and more important, some of the novel's criminal acts are disturbing to the point of gratuitous. So much so that at one juncture the (strikingly original) narrator offers a caveat: "If you are easily upset or have a sensitive stomach, I recommend you skip to the next chapter."

Skipping or staying the course, "Barcelona Shadows" emerges as a winning blend of moody atmospherics and supercharged thrills, and eventually resembles Pastor's description of the dastardly Enriqueta: "captivating and horrifying all at the same time."

Malcolm Forbes has written for the Times Literary Supplement, the Economist and the Daily Beast. He lives in Edinburgh.