The Lost Son (18) Screen at D'Olier Street, Dublin

Having won two Oscars for his cinematography on The Killing Fields and The Mission, Chris Menges turned film director with the memorable apartheid drama, A World Apart. Lured back into working as a lighting cameraman since then only by Michael Collins and The Boxer, Menges returns to directing with The Lost Son, a contemporary thriller starring Daniel Auteuil as Xavier Lombard, a French narcotics detective who, for reasons explained much later, moved to a new life in London where he works as a private eye. The drama opens Raymond Chandler-style as the private eye is hired by a wealthy couple (Billie Whitelaw and Cyril Shaps) to find their 28-year-old son, Leon Spitz, a Soho photographer and heroin addict who has disappeared. Lombard is persuaded to take the assignment by a former colleague (Ciaran Hinds), who has married the Spitz family's daughter (Nastassja Kinski).

Introduced as an opportunistic operator who is not beneath resorting to blackmail, Xavier Lombard is a lonely, dislocated exile whose few friends in London include a prostitute (Marianne Denicourt) he knew from the Rue St Denis. His quest for Leon Spitz takes Lombard to a remote area of Sussex, where he meets Leon's girlfriend (Katrin Cartlidge) and a traumatised 10-year-old boy.

For all his flawed pedigree, the detective finds that he still has the capacity for moral outrage and the will to act when he uncovers a truly sinister paedophile ring. Driven by a compulsion to take action, he poses as a paedophile to infiltrate the ring. Some scenes are skin-crawlingly disturbing as he makes his way through the layers of subterfuge which protect their identities and in the creepily business-like manner in which their shocking schemes are carried out. Leon Spitz, the lost son he is seeking, becomes a virtual McGuffin by this point in the narrative as Lombard's eyes are opened to the fates of lost sons and daughters who have been sold into slavery in the paedophile trade. Bristling with anger at what it reveals, the thriller is at its most tense and involving in this extended central sequence.

Although it loads on an excess of dramatic baggage in the over-plotted melodrama of its later stages, The Lost Son makes for strong, provocative cinema which pulls few punches yet never lapses into exploitation of its highly sensitive subject matter. It is in every respect more persuasive and compelling than Joel Schumacher's flashy and spurious treatment of a similar theme in the recent release, 8MM.

The Lost Son is distinctively shot on London locations by Ken Loach's regular cameraman, Barry Ackroyd, whose vigorous shooting style heightens the movie's edgy overtones. And that unsettling mood is anchored in the intense, all-consuming central performance of Daniel Auteuil in his assured first venture into English-language cinema.

Rogue Trader (15) Selected cinemas

Today's release of Rogue Trader, James Dearden's chronicle of the short rise and sharp fall of merchant banker Nick Leeson, coincides with the scheduled release of Leeson himself from a Singapore jail tomorrow week. Given a six-and-a-half year sentence for his illegal activities on the stock exchange, Leeson has had his time commuted by two years because he is suffering from stomach cancer. The film is based on Leeson's memoirs of the same title.

Dearden's film is just as sketchy in its account of Leeson's outrageous financial irregularities as it is in the arch asides about the bad diet which caused his cancer. Not unusually for a biopic, the movie's pivotal character is played by an actor far more attractive than the subject himself, with the slim, good-looking Ewan McGregor playing the balding, 16-stone Leeson.

The casting of the effortlessly charming McGregor cues the movie's essentially sympathetic spin on Leeson. From writer-director Dearden's point of view, Nick Leeson was an ambitious working-class lad making a fortune for his stuffy employers, Barings Bank, the world's oldest merchant bank, and a chirpy, good-natured chancer who saw the financial markets as "a great big casino" and played them with a recklessness that his employers blithely ignored as long as he kept the profits rolling in.

"It's like robbing Peter to pay Paul," observes Leeson at one point, "but hopefully I'd make enough money to pay back Peter before he found out." And for a while Leeson's nerve and tactical skills pay off on the floor of the stock exchange, a hive of frantic gesticulation and impulsive decisions. However, surviving potential financial debacles only encourages Leeson to take wilder gambles, and when he eventually loses, he incurs such massive losses that Barings becomes insolvent. The movie's crucial problem is its stolidly pedestrian nature, merely going through the motions to deliver a cautionary moral tale for our times. While the financial dealings are obviously too complex to explain in detail in the context of a feature film, the film unwisely errs on the side of oversimplification in all other respects too, and for all his star quality and the energy he invests in his performance, there is only so much that Ewan McGergor can do to elevate Rogue Trader above the limitations of its rudimentary screenplay.

The Mummy (12) General release

One of the old staples of the horror genre returns in Stephen Sommers's The Mummy, a mildly diverting but mostly overblown, special effects-driven production triggered by events during an expedition in the Sahara in 1923, when treasure hunters find an ancient tomb and unwittingly unleash the vengeful reincarnation of an Egyptian priest who has been sentenced to an eternity as one of the living dead.

Aspiring to the peaks of wit, panache and derring-do scaled by the three Indiana Jones movies, Sommers's film proves humourless and contrived, and for an adventure movie, it registers as singularly unadventurous when the human characters are left to their own devices without the benefit of special effects.

The eponymous mummified priest takes an inordinately long time to come back to life, by which time ennui has well set in, and even though the movie finally struggles into life when the mummy does, patience has been stretched to the point where its episodic structure is simply too obvious and its plotting too silly to generate any frissons of excitement.

While his co-stars Rachel Weisz and John Hannah appear to sleepwalk their way through the proceedings on automatic pilot, the reliable Brendan Fraser does all he can to spark the movie with his natural charm and his dry delivery of the movie's knowing throwaway humour. The special effects are impressive, as they ought to be given the big budget, although the ever-multiplying lethal scarabs seem more like shiny clockwork mice. Some sequences may well prove too scary for young children.

Simon Birch (12) Selected cinemas

The credits of writer-director Mark Steven Johnson's first feature, Simon Birch, state that it was "suggested" by John Irving's 1989 novel, A Prayer For Owen Meaney. In fact, Johnson's film has pared down Irving's remarkable novel to the point where the author demanded the change of title.

For all the wealth of wit, drama and keen observation they contain, John Irving's novels have proved difficult to adapt for the cinema, although George Roy Hill's The World According to Garp and Tony Richardson's The Hotel New Hampshire both deserved a good deal more credit than they received.

In his distillation of A Prayer For Owen Meaney for the screen, Mark Steven Johnson has jettisoned huge chunks of the novel, choosing to concentrate on one year in the life of the principal character, now named Simon Birch. Simon was the smallest child ever born at the hospital in Gravestown (Gravesend in the novel), and the doctors proclaimed his survival as a miracle.

Ten years on, the undersized Simon (played by Ian Michael Smith) is a precocious child who, generally ignored by his uncaring parents, spends most of his time with his best friend, Joe (Joseph Mazello) and Joe's loving single mother (the radiant Ashley Judd).

Conceived by Irving as a character who is treated like a joke but is firmly convinced he is "God's instrument", Simon is reduced by the movie to a shrill smart-ass in this all-too-literal reading of Irving's picaresque novel. This facile, saccharine film is accompanied by a schmaltzy piano-tinkling score from Mark Shaiman, interspersed with poorly-used 1960s pop singles.

Appearing fleetingly in the scenes which book-end the film, Jim Carrey is saddled with the maudlin and superfluous narration which offers such risible establishing lines as, "Weeks turned into months, and months turned into years."

The King & I (Gen) General release

Only a few contemporary references (flossing, for example) indicate that Richard Rich's animated musical treatment of The King & I is a recent production, such is the consistent blandness of its flat, unimaginative animation and the tritely caricatured nature of its characterisations.

Based on Margaret Landon's novel, Anna and the King of Siam, and the Rodgers and Hammerstein stage and screen musicals it inspired, Rich's film unwisely plays with its source material by adding such characters as a sycophantic but duplicitous prime minister (voiced by a stentorian Ian Richardson) and would-be cute creatures such as a wearisomely mischievous monkey - while reducing the tale's existing characters to stock stereotypes.

The film's account of the governess employed by the 19th-century Siamese ruler is further undermined by the anodyne Anna voiced by Miranda Richardson and sung by Christiane Noll. Only eight of the 20 songs featured in the musical are retained for this insipid movie, among them Get- ting to Know You and Shall We Dance?, which ensures that at least the songs are above the animation average.

On the evidence of some footage I saw last week, Andy Tennant's new live-action movie, Anna and the King, featuring Jodie Foster and Chow Yun-Fat in the title roles and due here in December, looks an infinitely more enticing prospect.