I think it was Raymond Chandler who remarked that if ever he got stuck in a story, he would have a man burst into the room pointing a gun. That usually kick-started things again. In an age of internet-fuelled esotericism, the author of today’s page-turner is as likely to reach for a cache of ancient manuscripts proving, through ley lines and the tarot, that Mary Magdalene/ Jack the Ripper was the founder of a secret masonic sect responsible for the 9/11 attacks.

Kate Mosse’s Sepulchre, a weighty follow-up to her novel Labyrinth, is very much in this vein. The worst accusation that one can make against the author of unabashedly commercial fiction such as this is that of short-changing the reader. No Beckett-style minimalism here, please – and nobody could accuse Mosse of failing to lay the plot on with a trowel.

So here goes. Sepulchre, set partly in the 1890s and partly in the present day, hinges on the discovery of a set of tarot cards in the very same French village that was at the centre of Dan Brown’s The Da Vinci Code. All that blood-line of Christ stuff was a cover-up for the real story. The tarot cards, which were buried with hidden Visigoth treasure, have the power to unleash demons – only the rumours of devilish beasts roaming the countryside were, in fact, put about by an aristocratic psychopath bent on revenge for a disappointment in love.

So much for the 1890s. In 2007, Meredith Martin, an American scholar (young, attractive – lots of flashing eyes and hair-tossing), comes to the village to investigate her ancestry and research her biography of Debussy (who also has a connection, because the structure of La Mer is based on the Fibonacci sequence). Her new-found English boyfriend, who part-owns the house (now hotel) at the heart of the mystery, is being murderously pursued by his uncle. He is after the Visigoth treasure, but luckily Meredith discovers that she is descended from the heroine of the 1890s story, and so has the power to unleash the power of the demons with the tarot.

Or something like that. The plot of Sepulchre is such a rambling and delicate structure that one has to tread carefully – some of its many corridors and byways one hardly dares venture down for fear that the whole edifice will come crashing down. But all this is beside the point. Sepulchre is what they call a thumping good read, which means that it socks you between the eyes with some occult widgetry (“Asmodeus, also known as Ashmadia or Asmodai, is most likely derived from a form or Persian, the phrase aeshma-daeva, meaning demon of wrath”), then follows up with the left hook of some sock-it-to-’em action. In books such as The Dumas Club, the Spanish writer Arturo Perez-Reverte has pulled off the lovely trick of combining the narrative excitement of this kind of stuff with a lively sense of the absurd (“sword in hand, tongue in cheek”, as one reviewer nicely put it). If Mosse has a similar sense of the ridiculous, she keeps it well under wraps. Then again, the comments of one snooty reviewer don’t amount to a hill of beans. A thing like Sepulchre is a steamroller of a marketing campaign, with a novel trailing along in its wake.

SEPULCHRE by Kate Mosse
Orion £18.99 pp550

Times Recommends

• The 100 Best Books of the Decade
• The Times picks the 50 best paperbacks of 2009
• The conversation: James Ellroy