Dir: Ole Bornedal. Denmark. 2007. 89mins
All children know that teachers are weird, but what if some of them turned out to be really weird - extra-terrestrially weird' This serviceable premise has yielded entertaining dividends before - notably in Robert Rodriguez's 1998 teen chiller The Faculty - and Danish spoof scarer The Substitute hardly breaks radical new ground.

Targeted at early teens and a couple of years below, Ole Bornedal's film scored highly on its June release in Denmark with its amiably spooky entry into the children's horror market currently characterised by RL Stine's Goosebumps books, Monster House and the darker recent additions to the Harry Potter cycle.

Visually polished, but with economical to-the-point narrative that gives it an agreeable touch of the Roger Cormans, The Substitute efficiently mixes its thrills with social comedy that will chime with younger viewers - mainly about the incorrigible awfulness of adults.

An arresting - to say the least - performance by Paprika Steen, one of the bona fide stars thrown up by the Dogme wave, should aid export, but lack of a truly distinctive angle on its material suggests the film is likely to score highest abroad as a fixture at children's film festivals.

A playfully ominous voice-over muses on the place of love in the universe, by way of introducing eerie goings-on in the countryside, where a sleeping woman is suddenly zapped into alertness by a glowing entity from another world.

The scene then shifts to a school where fractious kids are unimpressed by the announcement of a new supply teacher. But newcomer Ulla Harms (Steen) is more than they bargained for - a tough, sneering martinet and mistress of take-no-prisoners psychological games who announces she can bend them to her will, and proves her point with unearthly methods of mind control. It turns out she's an alien investigating the mystery of love in order to save her planet, where inhabitants devour each other after mating.

Prime victim of her classroom tactics is young Carl (Wandschneider), who finds Ulla mercilessly playing on his blind spot - his grieving for his recently-dead mother. The children complain about Ulla, but she bends the gullible, largely spineless local parents to her will, with a little help from a strange CGI globe that morphs itself into the shape of an education bigwig who vouches for her.

Bornedal - best known internationally for his 1994 horror pic Nightwatch, and its ill-fated 1997 US remake - directs with measured style. The film is generally higher on psychological chills and comedy than on special effects, although Ulla whips out a terrific jump-out-of-your-skin CGI metamorphosis to scare Carl. Largely, the humour plays on the differences between child and adult perceptions: when the kids visit Ulla's house, it's a bleak, creepy den, but it's transformed into the perfect home when the parents drop by.

Ulrich Thomsen provides engaging back-up as Carl's dad, a glum, confused philosopher, while co-writer Prip - better known as an actor - provides a relishably creepy character part as the school's narcissistic resident psychologist. The lively young ensemble cast led by Wandschneider are spot-on, even if they don't get time to develop their characters.

But the film belongs to Steen, playing it outrageously broad as a mercurial monster of a woman, slipping unpredictably from cackling witch to icy disciplinarian to cooing surrogate mum, sometimes within a single shot: her sometimes excessive performance is given that extra short of barminess by cleverly abrupt editing effects. An oddball running gag about poultry pays off in an appropriately surreal climax at a chicken farm.

Production company
Thura Film

International sales
Nordisk Film International

Michael Obel

Henrik Prip
Ole Bornedal

Dan Laustsen

Thomas Krag

Production design
Marie i Dali
Rie Lykke

Marco Beltrami

Main cast
Paprika Steen
Jonas Wandschneider
Ulrich Thomsen
Sofie Grabol
Henrik Prip