Peter and Kim drive up the Pacific Highway, with Tamara in the back and a caravan behind them. They’re looking for real estate, the right business. But Peter’s heart has business of its own. They can’t agree on anything south of the Queensland border. By the time they reach the Bribie Island turn-off, an hour north of Brisbane, it’s clear to Kim that Peter is driving, blindly or not, to Cairns.

They’ve already come more than a thousand miles with a cranky baby in a hot car; she won’t go another thousand, not for anything. She wants to go back to Sydney. They argue and turn the car south once more, but as Brisbane looms up in their windscreen again, she softens, knowing what’s in his head. There’ll be a registry in Brisbane, she says, births, deaths and marriages. Electoral rolls. Why don’t we have a look?

Years earlier he’d told her about the search for his mother. The blind running, questioning strangers, police, anyone. She’d looked at him, not quite believing. Then: Jesus, she’d laughed, that’s not the way you do it. Haven’t you ever heard of official records?

So here they are in the old sandstone building in George Street, and Kim is suddenly sure that this is it: this time, they’ll find her. It isn’t exactly what she’d planned for the trip but now that they’re here she’s made the decision: they’ll find her.

Now Peter is hurrying away from the inquiry counter waving the full copy of his birth certificate in the air: he’s only ever had an extract, and it hasn’t told him much. But this one has more names – those of Ernest and Veronica Ball – and these, she knows, are the clues they need.

They sit for hours, poring over telephone books and electoral rolls, as the baby sleeps and wakes and her cries echo up and off the beautiful high vaulted ceilings above them. Until Kim finds two sets of initials, E and V, that match up with the surname on the birth certificate, and she cries out too. I think we’ve found your grandparents, she says.

They drive to the address in Mt Gravatt listed in the electoral roll. An elderly woman in thick glasses opens the door, and Peter tells her he’s looking for Yvonne Ball. She looks him up and down, says, Who are you? He tells her who he is. Ronnie’s face betrays nothing. She’s expressionless. But something has registered because it takes her several moments to respond.

Then she says in her unschooled vowels: Oh, you’re Mick’s son. She won’t want to see you. There’s not an ounce of softness or regret.

But then she tells him to hang on; doesn’t ask him in, leaves him there on the landing at the top of the stairs while she shuffles away. Then she’s back and thrusting a piece of paper at him, an address scrawled in a shaky hand. He takes it and thanks her and leaves.

It’s a fifteen-minute drive from Mt Gravatt to Annerley, but it might be five or it might be fifty – they don’t notice. The car is a self-contained vessel, powered by emotion; Kim watches the play of anxiety and fear and excitement across Peter’s face. A sentence keeps playing in her head: We’re going to see his mother. She talks quietly to him, tries to calm him down, but she’s secretly anxious too, worried that it will all explode in front of them. She wonders what kind of picture they present, she and Peter and Tamara, and unconsciously she turns to the baby and checks she’s tidy. As she looks at her own child, another thought comes, something unexpected: how will she cope, this mythical mother, this long-imagined woman in Peter’s head? Kim’s a bit worried about her too.

They find the house, a white-painted Queenslander with bay windows and roses at the front, and park across the road. Before Kim can utter a word, Peter is out of the car.

He pushes open a gate between rose bushes and walks up the front stairs. Nausea growls in her stomach as she watches him. He is a boy once more, standing there; he might as well be holding his heart, torn from his chest, as the piece of paper that is still in his hands. But there’s no one home. He limps back and slides into his seat. They sit in the car and wait.

They look around them. By Sydney standards it’s an inner-city street, but there’s a suburban feel in its gardens and in the relative quiet. The house is similar to its neighbours: high-set and well tended, perhaps thirty or forty years old. An ordinary enough house, nothing to distinguish it, to set it or its occupants apart. Still, it tells them something of the people who live here: they’re not rich and they’re not poor. Well, not outwardly. The roses and the crisp white paint give it a homely feel, Kim thinks. It’s cared for.

With their quick nervous eyes they follow the steps of every woman who passes. Tamara has dropped off to sleep in the back. Kim is surprised – there’s so much adrenalin pumping around the car, she was sure the baby could feel it. And now there’s another woman on the footpath, and their eyes don’t miss a thing, not her energetic walk, her dark hair, the shopping she carries. They watch this woman – she seems the right age, that’s all they can tell – and for some reason they stop talking. As if words, sounds, might impede their vision, one sense diminishing the other. It seems important to be quiet. So they’re silent, their faces turned to the woman as she reaches the house. Stops. Turns into the gate near the roses. The roses, the roses. Oh my God, Peter breathes. That’s my mother.

She has walked home from work at the hospital today via the supermarket. Sometimes she’ll find one of her children waiting outside the laundry to drive her, a nice surprise but she never expects it, rouses on them for taking time out of their day. It’s only a fifteen-minute walk and pleasant in winter, though in summer she sweats freely, mopping her face, hating the heat.

She’s carrying a few groceries and doesn’t stop at the mailbox or among the flowers in the front garden, but walks straight past them and down the side path to the back steps. She doesn’t seem to notice the car and caravan parked across the street, or the faces turned towards her. Well, it’s a busy street in an inner-city suburb; there are always cars. She wants to move, when the youngest is finished school and university, to a quieter place and a low-set house. A couple of years earlier she fell down these steps as dawn broke on her way to work, needed surgery on a shattered ankle. It was the first bone she’d ever broken. She was proud of that.

In the kitchen she pushes open windows and fills the kettle. She is spooning coffee into a mug when she hears the knock at the back door.

She opens it to a good-looking, dark-haired man. Perhaps he’s somewhere in his thirties, it’s hard to tell. But her body feels a bolt of recognition; something opens inside her, then slams shut. It’s what she’s taught herself to do.

He says, I’m looking for Yvonne Ball. Her maiden name. She feels invisible fingers claw open a possibility. The man – for some reason she thinks boy – tilts his head and smiles. You don’t recognise me, he says.

The possibility.

Her heart, trained well by now, lurches. She puts her hand to it, admonishing. Casts around for any other name, mutters one, not his.

But the man on the step doesn’t seem to hear. He’s still smiling. Then: I’m Peter, he says, two words to stop the world. I’m Peter, your son.

She stands at the door and struggles to stay upright, to remain in that moment, looking at the face she’s sought so long. Lifts her hands towards him. Then notices the woman, behind Peter and several steps below.

The woman is smiling too, holding a baby. A girl, brown as a nut, dark-eyed. It is, she knows immediately, her granddaughter.

Would you like to come in? she says then, trying to control herself, her voice, her heart, her hands. What to do, what to say, how to be? Would you like some coffee?

She stands back. Peter steps over the threshold.

And there it is, cruel and sudden: the thirty-six years without her is manifest, tangible, in his limp, in his heavy, built-up shoe.