My brother, Will? But he lives in Manchester, and he has his own wife and twin boys, in a two-bedroom flat.

No. There is only one place I could go, if it’s not home.

My mobile phone is beside me on the pillow, and I pick it up, and scroll through the numbers until my finger hovers over his contact. Dad.

He has room, God knows. In his six-bedroom place up near Aviemore, where he lives alone. I remember what Will said last time he came back from visiting. ‘He’s lonely, Isa. He’d love for you and Owen to come and stay.’

But somehow there has never been time. It’s too far for a weekend – the train journey alone is nine hours. And before I had Freya there was always something – work, annual leave, DIY on the flat. And then later, getting ready for the baby, and then after Freya was born, the logistics of travelling with a newborn … or a baby … or soon a toddler.

He came down to meet Freya when she was born, of course. But I realise, with a pang that hurts my heart, I have not been up to see him for nearly … six years? Can that be right? It seems impossible, but I think it must be. And then only because a friend was getting married in Inverness, and it seemed rude not to call in when we were so near.

It’s not him, that’s what I want him to understand. I love him – I always have done. But his grief, the gaping hole left after my mother died – it’s too close to my own. Seeing his grief, year after year, it only magnifies my own. My mother was the glue that held us together. Now, without her, there are only people in pain, unable to heal each other.

But he would say yes. And more than yes, I think. He – alone of everyone – would be glad.

It’s gone seven when I finally dress, pick up Freya and go down to the kitchen. Through the tall windows overlooking the Reach, I can see the tide is low – almost as low as it will go. The Reach is just a deep runnel in the centre of the channel, the wide banks exposed, the sand clicking and sucking as it dries and all the little creatures – the clams and oysters and lugworms – retreat and shore up until the tide turns.

Kate is still in bed – or at least she hasn’t yet come down – and I can’t help a shudder of relief when I realise Freya and I are alone. As I touch the coffee pot – checking for any vestigial warmth – I find myself looking up to the turn of the stair, where I saw her face last night, ghost-white in the darkness. I’m not sure I will ever forget it – the sight of her standing there, watching us. What was her expression? Anger? Horror? Something else?

I run my hands through my hair – try to attribute a motive I can understand to her actions. Kate neither likes nor trusts Luc – and it’s plain now that that feeling is mutual. But why stand there in the dark like that? Why not call out, stop me from making whatever mistake she thought I was committing?

Why stand there in the shadows like she had something to hide?

One thing is plain, I can’t stay here – not after last night. Not just because of Luc’s warnings, but because the trust between me and Kate is gone. Whether I destroyed it with my actions last night, or whether it was Kate and her lies, it doesn’t matter.

What matters is that part of the bedrock of my life has cracked and broken, and I feel the foundations I’ve built my adult self on shifting and creaking. I no longer know what to believe. I no longer know what to say if I’m questioned by police. The narrative I thought I knew has been ripped and broken – and there is nothing to take its place except doubt and mistrust.

Today is Wednesday. I will go back to London on the first train I can catch, pack my bags while Owen is at work, and leave for Scotland. I can call Fatima and Thea from there. It’s only when a tear runs down my nose and splashes onto Freya’s head that I realise I am crying.

No one at Rick’s Rides picks up when I call, and at last I load the bags onto Freya’s buggy and wheel her out into the cool sunshine. I bump the buggy barefoot across the rickety bridge, and shove my feet into my shoes which are still there on the far side, like strange flotsam and jetsam. Beside them is a print of two larger soles – the imprint of Luc’s shoes – and I can see his footprints trail across the shore, and disappear into the muddy confusion of the track.

I let myself out of the gate, and begin the long walk to the station, talking to Freya as I go – anything to distract myself from the reality of last night and the mess of what’s facing me in London.

I’m just turning onto the main road, when I hear the hiss of gravel and a horn beeps from behind me, making me jump. I swing round, my heart thumping – and see an ancient black Renault, coming to a halt on the verge.

The driver’s window winds slowly down, and an iron-grey head looks out, unsmiling.

‘Mary!’

‘Didn’t mean to scare you.’ Her strong, bare arm rests on the window, the hairs dark against the pale skin. Her perpetually grubby nails tap the paintwork. ‘On your way to the station?

I nod and she says, as a statement, without asking for my opinion, ‘I’ll give you a lift.’

‘Thanks,’ I say awkwardly, ‘but –’ I’m about to use the car seat as an excuse, but then my eyes drop to the pram, where Freya is snuggled into the car-seat adaptor. Mary raises one eyebrow.

‘But?’

‘B-but … I don’t want to put you to any trouble,’ I say weakly.

‘Don’t be soft,’ she says shortly, swinging open the back passenger door. ‘Get in.’

Somehow I can’t find another excuse, and I strap Freya into the rear seat and then walk around to the front passenger door and climb silently in. Mary puts the car into gear with a coughing rasp, and we begin to pick up speed.

We drive in silence for perhaps a quarter of a mile, but as we round the corner to the level crossing over the railway, I see the lights are flashing, and the barriers are coming down. A train is about to pass.

‘Damn,’ Mary says, and lets the car glide to a halt in front of the barrier. She switches off the ignition.

‘Oh no. Does this mean I’m going to miss the train?’

‘This’ll be the northbound train for London, they’ve closed for. It’ll be cutting it very fine to get there. But you might be lucky. Sometimes they wait, if they’re ahead of themselves.’

I bite my lip. I have nothing I need to get back for, but the thought of waiting at the station for half an hour with Mary is not a good one.

The silence in the car grows, broken only by Freya’s snuffles from the back seat, and then Mary speaks, breaking the quiet.

‘Terrible news, about the body.’

I shift in my seat, moving the seat belt away from my throat where it has ridden up, and somehow grown tight.

‘H-how do you mean? The identification?’

‘Yes, although I don’t think anyone round here was surprised. There wasn’t many thought Ambrose would have left his children like that. He was devoted to those kids, would have walked through fire for them. A little local scandal? I don’t think he’d have even cared, much less scarpered and left his kids to deal with the fallout.’ She taps the rotting rubber of the steering wheel, and with an impatient gesture sweeps back a frond of grey hair that’s fallen out of her pigtail. ‘But it was more the post-mortem I was thinking of.’

‘What do you mean?’

‘Haven’t you heard?’ She casts me a quick glance, and then shrugs. ‘Maybe it’s not in the papers yet. I hear stuff early sometimes, what with my Mark being one of the boys. Perhaps I shouldn’t tell you, just in case.’

She pauses, enjoying the moment of power, and I grit my teeth, knowing that she wants to be begged for her insider information. I don’t want to give in to her. But I have to know. I must know.

‘You can’t leave me hanging like that,’ I say, doing my best to keep my voice light and casual. ‘I mean, I don’t want you to break any confidences, but if Mark didn’t tell you to keep it under wraps …?’

‘Well, it’s true he normally only tells me things if it’s about to be released anyway …’ she drawls. She bites her fingernail, spits out a fragment, and then seems to make up her mind, or tire of playing with me. ‘The post-mortem found traces of heroin in a bottle in his jacket. Oral overdose, they’re saying.’