Mental, (MA) 116 minutes. ★★★☆
IT WOULD be easy to imagine a glow of nostalgia around Mental. It reunites P. J. Hogan and Toni Collette, the writer-director and star of one of Australian cinema's most popular successes of the 1990s, Muriel's Wedding. And what brings them together again is a film with clear thematic and emotional links to Muriel.
Yet what makes Mental such a strong, surprising and in many ways uncomfortable film is its refusal to rest on any laurels: it's a strident, messy, diverting movie with some hard comic edges.
Mental begins by evoking The Sound of Music, visually and aurally: this movie is a touchstone of perceived ''normality'' in the mind of a middle-aged woman called Shirley Moochmore (an almost unrecognisable Rebecca Gibney).
Shirley is a resident of Dolphin Heads (a seaside town indubitably close to Muriel's Porpoise Spit). She's a fragile, good-natured character, the mother of five daughters, and she dreams of a family life that possesses what she regards as von Trapp-style perfection and unity.
But it's a long way from her actual experience. Her husband, Barry Moochmore (Anthony LaPaglia), the local mayor, is absent and uninterested - he can't even keep the names of his five daughters straight.
These girls, in their turn, are simmering with confusion, convinced they are social outcasts in the town and that they are all suffering from psychiatric illnesses.
Yet it's Shirley who snaps: she is dispatched to an institution while Barry seeks re-election, unencumbered by family dramas. Needing someone to look after things at home, he decides to hire a nanny, and the person he impulsively chooses is Shaz (Collette), whom he discovers when she is hitchhiking into town.
He has taken on rather more than he bargained for. Shaz is a feral Mary Poppins with a touch of Bill Sikes (she carries a knife, and is accompanied by a fierce dog). More important, she regards herself as ''an avenging angel of the perpetually humiliated'' and makes the female members of the Moochmore family her special project.
Mental has its lighter elements: it has a colourful, engaging surface, shot exuberantly by Don McAlpine. There's a strong supporting cast: some contribute broad comic turns, while others bring something extra to roles that require a little more depth. Gibney, who is absent for much of the film, contributes a crucial element of fragility and warmth. Lily Sullivan, as the eldest Moochmore daughter, Coral, is appealing, and the young actors playing her siblings give playful, credible performances.
Liev Schreiber, with a bristly beard and a convincing Australian accent, is Coral's employer at Trevor Blundell's Jaws of Terror, a shark attraction at the local amusement park. He's a bearer of gruff wisdom, and has a significant role to play in the way the Moochmore drama unfolds. And the figure of the shark becomes a surprisingly rich symbol for what is taking place around them.
Mental is not sentimental, although it has its emotional and poignant moments: it takes a bleak view of human behaviour and people's capacity for cruelty and self-interest. And it doesn't deliver redemption, at least not in predictable terms: it doesn't involve dramatic transformations or changes of heart, and it leaves most of its characters with their flaws and foibles intact. Its comedy can be brutal and broad, and its depiction of mental illness is more complicated and less straightforward than it first seems.
Shaz is an agent of change, but a troubled, erratic one: her mission on behalf of the Moochmores has a clearly uplifting aspect, but it's also delusional and extreme, and Hogan has no qualms about acknowledging that.
But Collette's performance anchors the film: it has a fierce, uncompromising quality that gives strength to the film's two interwoven tendencies - in-your-face comedy and emotional distress.
■Mental opens on October 4.