Comédie de l'innocence (98 mins, PG) Directed by Raúl Ruiz; starring Isabelle Huppert, Jeanne Balibar, Charles Berling

Raul Ruiz has been a prolific filmmaker for more than 40 years, first in his native Chile, then, after the fall of Allende, in France. But until the exquisite Proust movie, Time Regained, his films were regarded as too obscure to be shown here except at festivals and the NFT. But his latest movie, Comédie de l'innocence, were it in English, would appeal to the popular audience that enjoyed M. Night Shyamalan's The Sixth Sense and Alejandro Amenábar's The Others, both of which it resembles.

Adapted from the novel The Boy With Two Mothers by the Italian surrealist Massimo Bontempelli, Comédie de l'innocence is a subtly crafted psychological thriller. Or is it a ghost story? Ruiz keeps us guessing right up to the end, and even while providing a plausible explanation for what we've seen, he leaves us puzzled and puzzling over a mystery.

The movie begins straightforwardly enough on the ninth birthday of Camille (Nils Hugon), a precocious, somewhat unnerving boy, the only child of a well-off, middle-class couple who live in a grand mansion near the Eiffel Tower. There's something rather odd about the household. At lunch, his parents, Ariane (Isabelle Huppert) and Pierre (Denis Podalydès), sit facing each other at a large table with Camille to the mother's left and the father is constantly correcting the boy with his wife looking anxiously on.

Then Ariane's brother, Serge (the saturnine Charles Berling), turns up and we discover that he's a shrink, has his own floor upstairs, and that the house has been their family home for several generations. Ariane is much closer to Serge than to her husband, who is away for most of the film's action.

That afternoon, when Ariane joins Camille and the au pair, Hélène (Laure de Clermont-Tonnerre), in the park, her son abruptly informs her that she's not his mother and he's going to call her by her Christian name. What she first takes for a sign of childish pique begins to disturb, and she's weirdly intrigued when Camille says that he really lives elsewhere, in a less fashionable district of Paris. They take a taxi there and discover there's no one at the apartment.

But a middle-aged neighbour with a strangely knowing air (played by Edith Scob, famous as the heroine of Georges Franju's surreal masterpiece Les Yeux sans visage) lets them in after Ariane has claimed to be an old friend of the tenant. The flat is full of African statuary and while Camille appears to be at home there, Ariane has an asthma attack.

From the neighbour, she learns that the tenant, Isabella, lost her son in an accident two years ago. Ariane receives a telegram from this Isabella (Jeanne Balibar), and they arrange to meet. There ensues an extraordinary contest for Camille, whom Isabella believes to be her son, Paul, drowned in the Seine. Huppert and Balibar are cleverly matched by Ruiz and their scenes together create an electrifying tension. Confronted by the neurotic, yet strangely confident Isabella, the sensible, repressed Ariane begins to disintegrate.

Perhaps the boy isn't what she thought him, especially as he seems to be more attached to Isabella than to her. Meanwhile, brother Serge takes a psychiatrist's interest in Isabella's case, and it's revealed that Hélène, the au pair, is not the innocent she seems: she's studying probability theory, is Serge's lover and refuses to dine at the family's table. There's also another little boy we keep seeing: does Camille have an imaginary friend, as her mother thinks, or a real confidant?

The clever plotting constantly wrongfoots us and various hints direct us to numerous mythological and psychological undertones. There are refer ences to the tale of Tom Thumb. An engraving of the Judgment of Solomon hangs on the wall (and is defaced). The name Ariane suggests the classical Ariadne, whose life was undone after providing the thread to negotiate the labyrinth.

All the family's old furniture and possessions are apparently stored in the basement like buried memories. Serge has hung on to his toys and still plays with his electric trains, and seems less mature than the nine-year-old Camille, who spends his time recording the world with a small camcorder.

This eerie movie, in which the only violence comes with a couple of slapped faces, finds mystery in the most ordinary things. It ends up making us question the nature of accepted relationships and personal identity. Comédie de l'innocence is one of those pictures you emerge from looking forward to a second viewing.