An international co-production between the United States, Portugal, France, and Spain, the film is loosely based upon Arturo Pérez-Reverte's 1993 novel The Club Dumas.

[4] Dean Corso, a New York City rare book dealer, is hired by wealthy collector Boris Balkan.

Balkan has acquired a copy of The Nine Gates of the Kingdom of Shadows, a book by 17th-century author Aristide de Torchia said to be able to summon the Devil.

Corso hides Balkan's book in his hotel room and tells Kessler about the "LCF" engravings, proposing that each copy has three that together make an authentic set of nine.

The Girl and Corso track Liana to her family's ancestral manor where a Satanic cult are conducting a ritual using Balkan's book.

Balkan interrupts the ceremony, takes his copy back, and strangles Liana to death as the rest of the members run away in fear.

Corso finds a clue in Kessler's belongings that directs him to a remote castle, where Balkan is preparing to summon the Devil using the nine "LCF" engravings.

This is the authentic engraving, which depicts a woman who resembles the Girl riding atop a dragon-like beast in front of the castle at dawn.

[5] Pérez-Reverte's novel, El Club Dumas features intertwined plots, so Polanski wrote his own adaptation with his usual partner, John Brownjohn (Tess, Pirates and Bitter Moon).

[9] The film press reported, around the time of the North American release of The Ninth Gate, creative friction between Depp and Polanski.

Visually, in the neo-noir genre style, rare-book dealer Dean Corso's disheveled grooming derives from Philip Marlowe, Raymond Chandler's quintessential literary private investigator.

Barbara Jefford was a last-minute replacement for the German actress originally cast as the Baroness Frieda Kessler, who fell sick with pneumonia, and after a second actress proved unable to learn the character's dialogue; with only days' notice, Jefford learned her part, spoken with a German accent.

Selected prominent buildings in the film are: The musical score for The Ninth Gate was composed by Wojciech Kilar, who previously collaborated with Polanski on Death and the Maiden (1994).

The film's main theme is loosely based upon Havanaise, for violin and orchestra, by Camille Saint-Saëns;[13] some of the score has a vocalization (specifically, a melodic aria) by Korean soprano Sumi Jo.

[19] In his review for The New York Times, Elvis Mitchell said the movie was "about as scary as a sock-puppet re-enactment of The Blair Witch Project, and not nearly as funny".

[21] In the Los Angeles Times, Kenneth Turan said the film was "too laid-back, and unconcerned about the pacing of its story to be satisfying", because "while a thriller that's not high-powered, is an intriguing concept, in reality it can hold our attention for only so long".

[24][25] In Sight and Sound magazine, Phillip Strick said it was "not particularly liked at first outing — partly because Johnny Depp, in fake grey temples, personifies the odious Corso of the book a little too accurately — the film is intricately well-made, deserves a second chance, despite its disintegrations, and, in time, will undoubtedly acquire its own coven of heretical fans".