'I'm going to see Art,' I say. 'And I need to go on my own.'

'No.' Lorcan shakes his head for emphasis. 'You shouldn't confront him alone.'

It could be dangerous.

The unspoken words hover between us.

Is that true? Up until this moment I would have sworn that Art would never hurt me physically. But now I don't know what to believe. Now, everything is in chaos.

'I'm going to his office. I'll be safe there.'

'Fine, but I'm still coming. I'll drive you . . . wait outside.'

I nod. In truth I'm relieved. Right now I feel about as vulnerable as I've ever felt in my life.

'I'll just get a jumper, then we can go.' Lorcan disappears.

I am so tense I can't stand still. I pace across the room, impatient. He's taking too long. I can vaguely hear Lorcan on the phone. He's speaking softly and I can't make out what he's saying. I wonder who he is talking to. For some reason my mind skips to Hen. She called Art about Lucy O'Donnell's claims before I had a chance to speak to him myself. Was she warning Art then? Is Lorcan warning him now?

I force myself to sit down and take deep breaths. If I mistrust everyone, I will go mad. The image of Art holding Beth flashes in front of my mind's eye.

How can this be happening?

A minute later Lorcan is back in a wool sweater, and we set off. I stare out of the window as we drive through Hampstead and Belsize Park, down the hill towards central London. I barely notice the shops and houses we pass.

Art's business headquarters are near Exmouth Market, just off a trendy street full of boutiques and cafes. It's impossible to park on the road itself, so Lorcan turns down a side street.

He parks and turns to me, his forehead creased with lines of concern. 'Please be careful.'

I look into his eyes, holding his gaze for a few seconds. And then Lorcan reaches over and places his hand gently on the side of my face. His fingers are warm.

'Promise you'll call me if you think . . . if Art does anything that . . .'

'I'll be fine.'

I get out of the car and walk round the corner. As I cross the road and enter the lobby of Art's building, I realize I have no idea what I'm going to say.

It doesn't matter. Once we're face to face, I will work it out.

The security guard knows me and waves me through, into the lifts. I reach the fourth floor and walk into Loxley Benson. Camilla, the receptionist on duty, beams at me.

'Hey, Geniver,' she says. 'Thanks for the party. That New York shop where your sister-in-law got her shoes was wicked. Please tell her massive thanks for the tip. I've ordered a pair off their website. Gorge-ous.'

I nod as I pass her, too intent on finding Art to reply. I head for the glass doors that will take me through to the rest of the office.

'Er, Art's in a meeting,' Camilla says, suddenly sounding anxious.

I turn as I reach the doors. 'Which room?'

'Er, the boardroom,' Camilla says breathlessly. 'But let me call Siena.'

She's looking nervous. Is my rage that obvious?

I press my hand against the pad that opens the door out of reception. Like the permanent staff here, I enjoy finger-print privileges. The glass panel slides back and I walk into the corridor.

'Wait, please . . .' Camilla's voice fades as the sliding doors shut behind me. A few people are in the open-plan area from which the boardroom and private offices lead off. They glance over as I pass. I ignore them, head down.

I see him before he sees me. He's standing in front of the large table in the boardroom, holding court. Three men in suits are seated, staring at him in rapt attention. Art in full flow is a mesmerizing sight: all energy and intent. I know how those men watching him are feeling . . . how special he's making them feel.

For a second I hesitate. I have never, in all the fourteen years I have known him, burst in on Art in a business meeting. And then the image of him at the fire door of Fair Angel, holding our baby, erupts in my mind's eye. Fury boils up inside me. I grit my teeth and push the door open.

Art glances round, a look of carefully concealed irritation on his face. It turns to shock as he registers that it's me standing there. The men seated at the table are looking at me too, but I keep my gaze on Art.

'I need to speak to you,' I say calmly. 'Now.'

Art hesitates. Just a beat. I can see him weighing up his options. He clearly decides not to risk the scene that could ensue if he denies me what I want, and turns, smartly, to the waiting men.

'Please excuse me,' he says with effortless charm. 'This is clearly an emergency.'

In a single move, he's across the room, gripping me by the elbow and steering me away from the boardroom. People are staring as Art leads me down the corridor and into his own office. He holds onto my arm until we're inside, then he lets me go and shuts the door firmly.

'What the hell's going on, Gen?'

I swallow hard, trying to put my thoughts into words. 'I need to ask you something . . .'

'Ask me something?' Art blinks rapidly. 'D'you know who those men are?' He points in the direction of the boardroom. 'The PM's special advisers asking me me for more detail about policy measures that I suggested at yesterday's meeting.'

Light from the large window behind him creates a fiery effect around his head. He's almost crackling with fury. It strikes me again that, for all our time together, I have no idea what he's capable of.

'This is important, Art.' I meet his glare head-on.

'What's so bloody important?' he says. 'What do you need to ask me?'

I take a deep breath. 'I know our baby was born alive, Art. I know you took her and lied to me.'

'What?' Art stares at me. His eyes betray nothing but his anger. 'This again? For God's sake, Gen! How can you do this to me?'

He turns his back and clasps his hands behind his head. I can't work out whether he's buying time or simply trying to restrain his temper. Desolation swamps me. How is it possible I can be standing here, accusing my own husband of such a terrible crime? My stagnant, predictable life has turned into a vortex of misery and suspicion and I'm only just holding on, scarcely able to bear my own feelings.

I wander across the room. Art's large, airy work space is just like his office at home everything appears organized, and yet nothing is labelled. It strikes me that this is a perfect metaphor for Art himself: all artful organization on the surface; all controlled and hidden underneath. I stare down at the bottle of water and the spearmint chewing gum pack on the desk.

'I have to know the truth.'

He turns to face me. His eyes are hard but his mouth trembles with emotion.

'How dare you?' he spits. 'I know that bloody woman turning up on our doorstep was upsetting, but how can you possibly think . . .?' He breaks off.

'I've seen CCTV of you from the Fair Angel.' My voice shakes as I speak. 'I've seen the nurse from Beth's birth handing her over to you in the corridor.'

Art's eyes register horror, then the repressed fury takes over again.

'Impossible.' His voice is hard and cold as steel. 'Or faked.'

'That's ridiculous.' But I stop. Could the film I saw have been falsified? I hadn't even considered this possibility. My mind races over the ramifications . . . how can I find out? Would an expert be able to tell? Does this mean Art may still, after all, be innocent? Part of me hopes so, even as I'm recognizing that this would also mean the end of my dream of finding Beth. For the first time since I saw the CCTV footage, doubt enters my mind. 'Why would anyone bother to fake film of you with our baby?'

Art holds up three fingers. His eyes bore into me.

'One, to discredit me. Two, to drive a wedge between us. Three, to make you crazy. All of which are bloody happening.' He pauses. 'But that's just off the top of my head. I'm sure if you gave me a few minutes I could come up with another ten reasons. I can think of a million people who'd be happy to see me fail and you not trusting me is a failure for me, for my life . . . Jesus, Gen, it's a failure for us.' He's suddenly across the room, reaching for my hand, his whole demeanour beseeching. 'Please don't give in to this . . . this craziness, Gen. If it's not a fake film, then it must be all the pressure you're seeing what you want to see. It's . . . it's just in your head.'

It's so typical of Art to switch from logical reasoning to emotional plea like that. So typical. And so manipulative.

'Stop it, Art. Stop trying to make me feel like it's me . . . like I'm going mad.'

He studies me. 'But you know this is mad. You know it doesn't make any sense,' he says slowly. 'In your heart you know.'

For a moment I see him as an outsider would totally focused, totally sure of himself.

'Okay, so it doesn't make sense,' I say. 'But that doesn't mean it isn't true.'

I walk over to the shelf that runs from the window to the door. A single photo nestles among the row of business awards. It's a silver-framed picture of us on our wedding day. Art is smiling, his haircut preppily short. I'm gazing adoringly up at him. My hair is short too a gamine crop with a wispy fringe. It makes me look even younger than I was. It breaks my heart how young we both look.

And how innocent.

Art walks round to the other side of the desk. He stands in front of his chair.

'Gen?'

I lower my voice. 'Tell me the truth.'

'I am.'

'What about the money for MDO? I saw Doctor Rodriguez yesterday . . . I heard him talk about the money he was paid . . . was the MDO payment his first instalment?'

'No. I promise you, no.' Art grips the chair. His knuckles are white but his eyes are steady as they hold my gaze. 'Can't you see you're twisting everything to fit what you want to be true? Ask yourself why would I pretend our baby was dead? Why would Rodriguez risk being struck off and sent to prison? Why would I gamble my entire life on a lie?' His voice cracks. 'Gen, I have never wanted anything as much as I've wanted us to be a family. And . . . and it's not fair that you don't trust me when I suffered just as much as you when we . . . lost her . . .' He turns his face away so I can't see the emotion that is so unbearably obvious in his voice.

I suddenly feel exhausted. Can I really be wrong? Am I seeing links between everything because I can't bear the alternative that Beth is really dead?

Art turns round. His eyes are beyond miserable. I'm suddenly filled with doubt.

'How did you get hold of this film?' he says. 'Did someone help you?'

I flinch under his accusing gaze. And yet, why shouldn't I tell him . . . we've done nothing wrong.

'Lorcan helped me. We found the film at Rodriguez's house. He offered me a lift, that's all.'

'Really?' Art says sarcastically. 'How many little get-togethers between the two of you is that since the party? If he isn't halfway to seducing you by now then he's losing his touch.'

I've never heard such contempt in his voice. The doubts I was feeling just a few seconds ago vanish.

'That's not fair,' I say, stung. 'Lorcan just wants to help.'

Art lets his breath out with a sigh. He shakes his head. 'So a man you've never met before drops everything to take you wherever you want to go, and you don't even question his motives.'

'It's not like that, I-'

'Whereas I . . . I love you. I've known you for fourteen years and been married to you for twelve. But you think I'm capable of betraying you without any proof whatsoever.' His voice rises. 'Don't you remember what Lorcan did here . . .' He waves his hand to indicate the Loxley Benson offices.

'You mean having a one-night stand with someone's wife years and years ago?'

Art opens his mouth as if to say more, then clearly thinks better of it. 'Never mind Lorcan,' he says. 'I'm seriously worried about you.'

'I saw you with a baby,' I insist. 'You were at the Fair Angel hospital.'

'Are you sure? Think about it,' Art pleads. 'Are you seriously saying I've somehow "got rid" of a perfectly healthy baby that I wanted as much as you? How could it even happen? Dr Rodriguez pronounced Beth dead. There were other people in the room.'

'Yes, but most of them had to leave before the birth because Rodriguez deliberately gave them food poisoning. And the two who were present are both dead.'

'I saw her body.' Art carries on as if I hadn't spoken. 'You know how much I want a family. It's me pushing for the IVF right now. How does me taking our baby away from us make sense? How does any of this make sense?'

I don't have any answers. A few moments pass. Through the window of Art's office I can see people peering in at us. There's Kyle and Tris and a couple of the PAs. They're all pretending to talk or work, but they keep glancing in our direction.

'I agree it doesn't make sense,' I say. 'But there're all these things I've found out: I heard Rodriguez talk about the money he got. I saw the baby in your arms the night we had Beth.'

'No.' Art thumps his desk. 'No, Gen. All those things are just coincidences or misunderstandings. You're making everything add up to me being guilty because above and beyond anything you want Beth to be alive. You said as much after we saw Mr Tam. You didn't want another baby because you still wanted Beth.'

I back away, my gaze still fixed intently on Art's anguished face. He takes a step towards me.

'Where is this film that supposedly shows me with the baby?'

It's actually in my pocket but I'm not admitting that to Art. If I let him have the film, then he's in control, and I want a chance to check out its authenticity for myself.

'I don't have the film on me,' I say. 'It's somewhere safe.'

'I want to see it,' Art demands. 'Whatever you think it shows it's a fake.' He hesitates. 'I'm going back to my meeting, but I want you to stay here. Afterwards we'll go home and look at this film together. And then I'm taking you to see a therapist.'

'What?'

'Please, Gen. This has got to stop.'

I stare at him. The blood is throbbing at my temples. Art's not going to admit to anything. He's turning it all onto me. I realize, with a terrible, sickening misery that I no longer trust him.

'Fine.' I turn and stare out of the window. The sun is shining in, highlighting a line of smudges across the bottom of the glass. It's a cold, clear day and from here I can see all the way across the river. The light is sharp, the tallest buildings delineated against a bright blue sky.

Behind me the door shuts. Art has gone.

I have to tell the police. Maybe the CCTV film on the memory stick in my pocket is a fake, but I need to know for sure. They can check Loxley Benson's books . . . they can track the money Art paid to MDO and find out whether it somehow made its way to Rodriguez.

I slip out of Art's office. Avoiding the boardroom, I walk through the open-plan area. The younger guys are there sharp-suited and slick-haired, hunched over their computers. I have to stop myself from running as I reach the corridor off which the board members all have offices. Tris sees me as I pass and calls out 'hello'. I act like I haven't heard.