I followed her out of the room and up the stairs to a narrow landing. She opened the door to a box room. It was a little girl’s bedroom, with cream walls and a small chest of drawers painted with stars and moons. A jewellery box rested on top. A clown doll, with a soft body and chipped china face, sat slumped against it.

A single bed, squeezed in against the far wall, was covered with a bobbled pink counterpane and a cushion with an appliqué dancing elephant. The elephant’s tutu, a semi-circle of starched white net, stood proud from the fabric.

A row of soft toys sat along the length of the bed, their backs against the wall. Teddy bears with red ribbons, a knitted rabbit, a giraffe, felt dolls.

It was too still, too tidy. The sunshine streaming in through the small window danced with motes of dust.

She pointed, inviting me to step inside. There wasn’t a lot of room. A low table sat behind the door. It was piled with brand-new toys.

Dolls in unopened packaging. Jigsaws, still in cellophane. A shiny box of building bricks. Packet of pristine crayons, paints, felt tip pens. Above it all, a framed drawing of a large, ornate letter ‘K’. On the end of the table stood a bud vase with a single yellow rose, its petals already loose and starting to fall.

I turned back to her. She was watching my confusion, her expression sad.

‘Katy’s room?’

She nodded. She opened the padded envelope, tore off the wrapping paper I had taped with such care and placed the box on top of a jigsaw. The little girl, her wrists decorated with plastic bracelets, smiled up at us both. The room was lifeless.

‘She doesn’t live here, does she?’

‘Not exactly.’ She frowned. ‘But we like to feel she’s here.’

She ushered me out. The door directly across the landing was open, showing a second bedroom. That one was clearly occupied. I crossed to the threshold and peered in.

The walls were a neutral beige, the carpet and curtains dark blue. The jazzy duvet on the double bed was crumpled as if it had been pulled across in haste. The bedside table was piled with books and scraps of paper.

A pair of men’s trousers hung across the back of a chair. Used socks and a pair of underpants were strewn on the seat. Across the bottom of the bed, an abandoned sweater. Matt’s sweater.

She stepped past me and stooped to pick up the dirty washing, then dropped it with a low sigh into the canvas laundry basket by the door. It was an automatic gesture that suggested years of repetition, years of arguments.

I looked again at the line of her jaw, the shape of her eyes.

‘You’re his mother.’

Her forehead creased, worried. ‘I am.’

I looked back towards the box room. ‘Katy’s grandma.’

She nodded.

I shook my head, looked again at the messy male room. ‘He lives here?’

‘He didn’t tell you, did he?’ She reached forward and patted my arm. ‘He’s a good boy. Don’t be angry with him. He really cares for you. I’m his mother, you see. I know. He just hasn’t been himself. Not since we lost Katy.’

I stepped further into his bedroom. Along the wall to my left, partly hidden by the door, hung a long cork noticeboard. Its surface was covered with a mess of black and white pages, stuck with coloured pins. Grainy photographs, printed off from a computer. My stomach contracted. I went across to look more closely.

Pictures of me. Walking through the shopping centre. On the high street. Outside nursery. Standing in the park. Images of our home. Some taken from the far side of the road, shot through parked cars. Others from right outside the house, from the gate. They were scribbled with marker pen. Hearts drawn crudely round my face. A cartoon flower stuck in my hand, another in my hair.

Several were dark, taken at night. Dim close-ups of the shadowy front door. An image of my bedroom window, a line of light tracing the edges of the curtains. ‘How dare he.’ I turned back to her, angry now and slightly sick. A memory rose in me from those weeks just after your accident when I felt most vulnerable and had a sense of being watched, of being followed, of glimpsing a figure in the shadows, staring at the house through the darkness from across the road.

‘He followed me, didn’t he? Before we really knew each other. He spied on me.’

She spread her hands by way of apology and inclined her head.

‘He didn’t mean anything by it. He just wanted to protect you. He felt it was, well, his mission.’ She hesitated. ‘He’d never hurt you. You know that?’

I didn’t answer. I didn’t know anything any more.

She guided me back downstairs and into an armchair. She set a glass of water in front of me and I drank it off, my head spinning. All I wanted to do was to run out of that mummified house and go home, lock the front door and crawl into bed. To hide away from all the confusion, the hurt, the betrayal. My legs shook and she seemed to pin me there, with her politeness, with her kindness.

‘You have to understand, it’s an illness.’ Her eyes never left my face. ‘He can’t help it. It’s a tragedy, really. He could have done so much more. He was always clever. Did well at university. And he almost qualified, you know, as a doctor.’ She hesitated, reading my shock. ‘Ah. That’s what he told you, isn’t it? A doctor?’

I stared, shaking with fury. I felt stupid. Tricked. Who was this man who had walked into our lives and lied to me? Who deceived me, abused me.

She went quietly on. ‘Matthew works in a restaurant. The smart restaurant at the hospital, on the top floor. Have you tried it? A bit pricey but very nice food. It’s not a bad job. He’s very reliable and he cooks well, don’t you think?’

Her look was almost sly as if she knew, as if she could see him there in my kitchen, my apron round his waist, his strong arms chopping and cutting, grating and stirring. As if I should have known.

‘They didn’t plan the baby. But once he got used to the idea, he wanted it desperately. You’ve no idea. He loves children. And then, when they lost her…’ She trailed off, gazing past me at the wall, unseeing. ‘It was devastating. And then she left him almost at once. It was cruel, really. It was more than he could cope with.’

I put my face in my hands. My temples throbbed. ‘I should go.’

‘He said you were different, Jennifer. That you might understand. He told me about all you’ve been through with your husband, with your little girl. We’re both so sorry.’ She hesitated, her eyes back on my face, beseeching now. ‘We’re two of a kind, Mother. That’s what he said. Two of a kind.’

‘I went to his flat.’ I thought of the stylish block and the contrast it made with this place. ‘He doesn’t have one, does he?’

‘Oh dear.’ She looked away. ‘No, I’m afraid not.’ She leaned forward, stacked the plates and cups on her tray.

I sat there, stupid with shock. She got quietly to her feet and carried out the tea things. I looked down at the swirling carpet and pictures seemed to form there. Matt, appearing from nowhere as I sat, alone and desperate, in the hospital café. Matt, appearing on the high street as I walked you home from nursery. Matt in the kitchen, capable and confident as he cooked. Matt, sitting silently in your darkened bedroom, hunched forward, his eyes sad.

When she came back, she was carrying a large box. She seemed pleasantly surprised that I was still there. She set the box on the table between us.

‘What about Geoff?’ I said suddenly.

‘Geoff?’ She blinked.

‘He doesn’t have a brother, does he? A policeman. A detective.’

Her face seemed to crumple and she looked down, fiddled with the lid of the box.

‘How could he tell so many lies?’ I was on my feet, my hands balled at my sides. ‘Everything. Everything he’s told me!’

‘Not everything, Jennifer,’ she said very quietly. ‘You mustn’t think that. He does care for you.’

The room was unbearably oppressive. I strode through to the kitchen. Compact, neat, ordinary. The tray sat on the worktop. The cups and saucers, already washed, sat upside down on the draining board. I stood there at the sink, looking out at a small handkerchief of garden. The borders were planted with rows of white and yellow alyssum. The square of lawn in the middle was freshly cut. I imagined Matt, his sleeves rolled up, pushing a mower up and down the patch of grass, straightening the edges with shears while his mother, pottering in the kitchen, watched from the window.

I ran the cold-water tap, splashed my eyes, my face, trying to steady myself.

He was never a doctor at the hospital. He chopped vegetables and stirred soup for a living. All the stories he told me about difficult nights, about desperately ill children, they were all lies. What a fool I’d been.

I went back into the sitting room where she was steadily emptying the contents of her box onto the table.

‘They didn’t know anything was wrong,’ she said. ‘No one did. Matthew painted the nursery. They had everything ready, the sweetest little booties, dresses, bonnets, everything. Then they went on that silly holiday. I did advise against it but they wouldn’t listen. They rushed to the hospital and it was too late.’ She paused, remembering. ‘Poor things. Imagine. Having to go through all that. To give birth to a child who’s already passed away.’ Her voice caught and she hesitated, collected herself. ‘It doesn’t bear thinking about, does it? Please try, Jennifer. Try to find pity in your heart for him.’

I turned to her to say goodbye. I thought of Matt and his sad little life, pictured him striding into this dim room in the evening, sitting with his mother, watching television. I shook my head. I never wanted to see this wretched house again.

‘I’m sorry,’ I said.

She pulled out a thin cardboard folder and opened it, held it up for me to see.

‘This is Katy.’

I looked down at the photograph. I recognised it at once. A sepia study of a newborn with closed eyes, wearing a sleep-suit and a tiny hat with lace trim and lying in a Moses basket. A sticker on the mount said: Portraits by Stella. On the table, beside the box, nestled in tissue paper, lay a lock of ginger hair.

‘Ella was his ex, wasn’t she? It was his baby she lost.’ I pointed, my voice sharp. ‘Catherine Louise.’

She shrugged, smiled. ‘She preferred Catherine. But we always called her Katy. It was my mother’s name too, you know. And besides, Catherine is such a formal name for a baby girl. Don’t you think?’