British TV veteran Tom Shankland wears his influences on his sleeve in his feature debut, W?Z, a serial killer chiller whose nasty atmosphere (and stylised title) owes much to Bryan Singer's Se7en (1995), while its luxuriation in torture and gore derives from such Splat Pack outings as the Saw series.

At the centre of proceedings is the Price Equation, which was devised by the US geneticist George R.Price to provide a mathematical basis for evolution and natural selection. However, a lot of blood has to be shed among the lowlifes of New York's gangland before world-weary cop Stellan Skarsgard and perky new sidekick Melissa George come to realise its relevance.

Skarsgard initially suspects crackhead thug Tom Hardy of the waterfront murder and mutilation of a rival leader's pregnant girlfriend. But he's put straight by a whoppingly contrived Macguffin - Alfred Hitchcock's term for a plot device that's superfluous in itself, but has considerable knock-on significance - which comes in the form of a rare anaesthetic that brings Skarsgard and George into contact with Paul Kaye, a sinister scientist who just happens to have the telltale equation on his blackboard and can explain how someone might be driven to kill to protect a loved one from torment. Suddenly aware of his own part in the mystery, Skarsgard tries to protect snitch Ashley Waters. But he succeeds only in delivering them both into the hands of the vengeful Selma Blair, who has set up a chamber of horrors that Boris Karloff would have killed for.

The denouement is dark and disturbing and admirably played with downbeat menace by the underrated Blair. Moreover, Danish cinematographer Morten Soborg creates a suitably depraved urban landscape (which recalls both Martin Scorsese's Taxi Driver and the Pusher films that Soborg shot for Nicolas Winding Refn), and there's also something intriguing about a scenario based on a formula for disproving the existence of altruism. But Clive Bradley's screenplay is pitted with cavernous plotholes and, for all its vile intensity, this always feels as though it's teetering on the brink of parody.

d=3,3,1The winner of the Best Screenplay prize at Cannes, Edge of Heaven, Fatih Akin's treatise on the capriciousness of existence, consistently recalls the great melodramas of Douglas Sirk and Rainer Werner Fassbinder. It's no accident, therefore, that Hanna Schygulla should feature so prominently, as the German mother of the murdered Patrycia Ziolkowska, whose last wish is for Schygulla to secure the release of her jailed lesbian lover, Nurgul Yesilcay, from a Turkish jail. However, the latter is also being sought by Istanbul bookshop owner Baki Davrak, whose father (Tuncel Kurtiz) killed her ex-prostitute mother (Nursel Kose) in a jealous rage.

Revelling in the coincidences of life and the contrasts between diametrically opposed cultures that are increasingly being intermingled by migration, Akin judges the tone and pace of this transcontinental saga to perfection. Moreover, he sustains an authenticity that prevents the consciously contrived storylines from lapsing into soap operatics.

This is particularly true in the case of Schygulla's journey to Istanbul to see where her daughter was killed by some street kids. Not only does she receive assistance from Bavrak, who had been Ziolkowska's landlord, but she also reaches a rapprochment with Yesilcay, to whom she had only previously shown hostility. To some, this would seem trite and novelettish. But this exploitation of fate is directly inspired by the likes of Sirk's Magnificent Obsession (1954) and Fassbinder's Fear Eats the Soul (1973), which itself was a remake of Sirk's All That Heaven Allows (1955). That said, Akin is more politically astute than either of his mentors and, consequently, Edge of Heaven is a more realistic and provocative insight into human nature and the complexities of modern society.

Changing tack completely, Annie Leibovitz: Life Through a Lens is a documentary profile of the US photographer who supposedly ruffled the Queen's feathers last year. With precised efficiency, it chronicles her globe-trotting youth, her wild days as a snapper for Rolling Stone magazine and her emergence as Celebrityhood's favourite portraitist.

However, as the director is Leibovitz's sister Barbara, the tone is often reverential to the point of hagiography. Consequently, potentially fascinating topics like her drug abuse, her lesbian affair with Susan Sontag and her freewheeling relationship with her young children are either skirted or sanitised. Leibovitz still comes across as a driven, intuitive artist, but the image has all too obviously been airbrushed.