It opens in Seattle in June 1998, when Amina receives a call from her mother, Kamala, in Albuquerque, New Mexico, to say all is not well with her father, Thomas, a respected neurosurgeon who, while sitting on the porch after work late at night, appears to be talking to Amina's grandmother, Ammachy, who has been dead for almost 20 years. Despite the demands of her busy job and the knowledge that her mother is prone to exaggeration, Amina flies home to find out for herself what, if anything, is wrong with her father.

Jacob takes the reader by the hand and effortlessly, skilfully, leads them ever deeper into this irreverent and deeply engaging story of grief and loss, despair and optimism, love, longing and family secrets.

Moving back and forth between Seattle, Albuquerque and India, between the present and the past, the novel also cannily probes notions of voyeurism, secrecy and the nature of disconnection and rupture within families through Jacob's gentle, witty lyricism and some sharp dialogue.

It is dialogue that sparkles with the syntax, rhythms and dynamism of the subcontinent in parts and glimmers with a wry, dry American humour in others. Amina's closest confidante is her "cousin" Dimple, daughter of her parents' closest friends, the Kurians, Hindus from India's south who had emigrated to New Mexico in the 1960s, along with her own parents, Surianis or St Thomas Christians who trace their religious roots back to AD50.

Dimple, who has also moved to Seattle where she runs a photographic gallery, warns Amina that Kamala is using Thomas as an excuse to lure her back home, "where she can get you married. Before your uterus dries up". It's something Amina's mother has tried to do in the past - 12 times in fact; 11 times without her permission. All with boys from the Suriani community, which Dimple insists on calling "the stalest community on earth", or "India's WASPS". In contrast, Amina is in awe of the speed with which Dimple has worked her way through Seattle's eligible bachelors.

But then, according to her mother, Dimple has been "afflicted with low morality" since the day her parents named her after "giggly Gujurati starlets". Kamala, who has fallen under the spell of a succession of Christian evangelists, expresses her disapproval of Dimple at every opportunity.

A far safer subject to discuss with Kamala is her cooking. A diminutive and difficult woman, her mother has the "ability to transform raw ingredients into sumptuous meals", observes Amina, "that brought her the kind of love her personality on its own might have repelled".

Just as Kamala's chutneys and appams, vindaloos and kormas serve as a kind of salve to the family's wounds, food serves as a secret language in this novel, which, in Jacob's inspired and fresh telling, manages to say something new about the nature of family dysfunction and the immigrant experience.

Amina still recalls the violent family argument that coloured the last visit to Thomas' mother and brother Sunil in India when she was 11. An argument that had ruptured the family's ties to Ammachy, Sunil and India, and had ended in the angry, horrible words that had eerily presaged the greater loss to come: the loss of Amina's intellectually gifted brother, Akhil.

In returning home, where Akhil's room remains much as it was, Amina plans to confront her father about his nocturnal chats, but Thomas avoids the issue. So, too, do his colleagues at the hospital where he works. Instead, the visit forces her to confront her memories of Akhil, who struggled with his own demons.

She revisits much of their early life together where they witnesses their parents' unhappiness, their mother longing to return to India while their father buries himself in his work at the hospital and in the Indian Christian community in New Mexico. But even as we are taken ever deeper into Akhil's story and their shared life at school and at home, the circumstances of Akhil's death remain a mystery - one compounded by the gradual revelation of more secrets that are peeled back so subtly that the novel reads at times more like a mystery than a family saga.

There is also mystery surrounding a photograph of a native American activist jumping to his death off a bridge Amina took early on in her photographic career. Yet the memory of this image and the unwanted notoriety it brought her haunts Amina and compelled her to abandon her promising career as a photojournalist and work instead as a wedding photographer. It was Dimple who helped her land a demanding job at the upmarket Wiley Studios, with its even more demanding boss. But what no one knows is that Amina keeps a cache of compromising photographs of her wedding subjects hidden in her closet - a cache that will have powerful consequences later in the narrative.

Meanwhile, her mother, living up to her previous form, sets up a match-making dinner with a young Indian neurosurgeon who works with Thomas, igniting an argument that sends Amina scurrying back to Seattle. But on the drive to the airport, she learns of the extent of Thomas' erratic behaviour from his hospital secretary who reveals what they've all been keeping secret: that he'd tried to revive a dead youth in the ER a few weeks previous.

Horrified, she risks the opprobrium of her boss in Seattle to stay with her parents, where the awful truth behind Thomas' uncharacteristic behaviour finally comes to light. But not before Amina has rekindled an old college romance and started seeing ghosts of her own.

Jacob sustains the momentum of this luminous, page-turning novel with a dexterity rarely found in debut novels. Examining the nature of the ties that bind us, be it to place or people, with a raw and beguiling honesty, she brings the many tangled threads and secrets of this narrative together, both past and present, in an ending that is as uplifting as it is heartbreaking.

But the real triumph of this novel lies in the characterisation. Of Jacob's believable and memorable characters, none will leave you indifferent, least of all Amina, the voyeuristic narrator. Even the Eapens' dog, the ageing, arthritic Prince Philip, takes on fictional life while those characters with a human face linger in the consciousness long after the novel's end.

And yes, for the record, some of Jacob's characters do sleepwalk, some even dance in the literal sense. But it is in sheeting home the universal, life-affirming sense of both that this novel truly excels.