Just picture this

You are driving through Brittany in torrential rain when a bolt of lightning strikes a tree in your path, blocking the road. From the other side of the tree the driver of an elegant Rolls-Royce emerges, who claims to be an art dealer with urgent business across the Channel, and no time to double back for a detour. Why wait for the tree to be cleared, he suggests. Why not simply swap cars for a few days? Such is the opening gambit of Gilbert Adair's new novel, The Key of the Tower. It is only the first in a series of bizarre happenings that plunge Englishman Guy Lantern, on what was meant to have been a Breton holiday, into a crisis every bit as existentially harrowing as that endured by Jean-Paul Sartre's Roquentin in nearby Le Havre.

First, someone tries to steal his Rolls-Royce in St-Malo. This turns out to be Sacha, surly partner of the art dealer Cheret. Through Sacha, Lantern encounters Cheret's wife, the chic and beautiful Bea, with whom (like Sacha before him) he promptly begins an affair.

Sacha and Bea have recently bought a painting by Georges de la Tour, entitled La Cle de Vair, from an unsuspecting local solicitor, and are planning to sell it on for £10 million to a Lebanese billionaire, Nasr, who lives in England. Hence Cheret's urgent summons. Not that they or Nasr have let him in on the deal; the painting was concealed in a secret compartment in the Rolls-Royce. The non-arrival of de la Tour has not gone unnoticed by the billionaire, whose Proust-quoting heavy now lurches into action, with a Mohicanned catamite in tow. By now, however, Sacha's jealousy of the narrator has led him to decamp to Mont St-Michel with the canvas. A grotesque chase ensues, in the course of which Lantern and Bea escape from Nasr's heavies to a local golf club and Lantern learns that "On a golf course" is not in fact the correct answer to the inquiry "Where do you play?"

The final scene, in Sacha's studio, completes the narrator's disorientation and the collapse of the novel into self-reflexive farce. Lantern kills Sacha in self-defence, then learns that it was Sacha, a talented copyist but devoid of originality, who painted La Cle de Vair; he even wrote an art book specially in order to include a description of the painting and so arouse Nasr's interest.

Bea quotes the book's ISBN number to Lantern to prove she is telling the truth; needless to say, it is also the ISBN number of The Key of the Tower itself.

Enraged at the deception, Lantern shoots out the faces of the figures in the painting, which are modelled on Sacha and Bea, before shooting Bea as well. Driving away from the scene, what should he see on the road but his own car driving towards him, Cheret returning from England as planned. He swerves violently, but so does Cheret. A crash seems certain, bringing back memories of the novel's opening.

Adair has translated Georges Perec, and handles his French setting with an affectionate sureness of touch. Less sure is the second-hand Nabokovian tone, which comes close to pastiche at times. The plot of the novel, while droll enough in its way, is not unlike the devilish machine described in Adair's epigraph: whirring and mechanical, but little more than a gimmick. By the time Lantern's car reappears on the last page, he isn't the only one with the suspicion that somehow he's seen it all before.

David Wheatley is a poet and critic