The Night Guest, By Fiona McFarlane: Book review - a suspenseful debut novel about ageing and illness from a talented young voice

There is an irony to so many young novelists writing about dementia (Samantha Harvey's The Wilderness, Jonathan Franzen's essay "My Father's Brain", to mention just two). In some respects though, it isn't ironic at all.

Dementia is one of today's biggest rising afflictions but aside from the devastating medical and human implications, it is an illness that may be ripe for fiction, bringing with it questions of upended identities, of what remains after one's memory is rubbed out, of the creative "insanity" that a neurological illness can bring, the disturbing (could it also be liberating?) blurring of lines between reality and fantasy, and the encroachments of imminent death.

So we come to Australia's Fiona McFarlane and her debut about an elderly woman – a proud, respectable, wealthy woman – with two grown-up sons and a deceased husband, who now lives alone in a house by the sea, or alone until she hears – feels – a tiger padding around in her home. Ruth rings her sons and before she knows it, a helping hand has arrived in the shape of larger-than-life Frida, a government carer who begins by cleaning the house for a couple of hours each day and ends up living in the spare room.

Ruth can't remember asking Frida to move in; the carer insists that Ruth is losing her memory. For a while, the reader is unsure of which reality to trust. The narrative, delivered from Ruth's point of view, slowly unravels so that we see her mental fragility. Is this dementia, or is it an old woman's response to a crafty imposter? Soon enough – perhaps sooner than McFarlane would have liked – we understand where deception lies, but this penny-dropping moment is not the raison d'être for this glittering debut.

Even if we can foresee the doom-laden ending, there are other ways the story grips us. The relationship between the two women never achieves total co-dependency nor the kind of master-slave dynamics we saw in Notes on a Scandal, for example. This book is not as much about their relationship as it is about Ruth's old age, loneliness, her decision to need Frida, to let her in, and the courage that decision entails.

The Night Guest's precise and elegant prose has been praised by Kate Atkinson and Evie Wyld among others, but what really stands out is its portrayal of one life lived, told with a fullness that is reminiscent of another masterful antipodean novel – Emily Perkins's The Forrests. What is most tenderly depicted is Ruth's backward reflection on her life choices – her marriage, unfulfilled romances, her role as wife and mother. This forms the heart of the book, outside the thriller-ish plot, and it is rendered with extraordinary maturity for such a young writer.