I remembered the fight she had got into on the first day of the war. My sister was a force to be reckoned with. What is she going to do? I wondered. Push the policeman off the cliff? Rip open the door of the police car and rescue Mutti? In that moment, striding forward, with her mess of brown curls streaming out behind her, my big sister looked ten feet tall, like some sort of warrior queen. I had complete and utter faith that she was about to save the day.

But she didn’t push the policeman or even go near the police car; she turned towards the ridge. Then she broke into a run, and stumbled up the path towards the south cliff.

She’s gone. She’s left me. I blinked a few times and shook my head, as if trying to wake up.

Pa came back inside and the two policemen came in after him.

‘Mind if we have a quick look around while we’re here?’ they asked Pa. He nodded helplessly and sank down on to a kitchen chair, his face slack with shock.

The thin man in the pinstriped suit sidled through the kitchen door too. Where had he come from? He must have been sitting in the back of the police car with Mutti, but I hadn’t noticed him. He didn’t say anything at all, just nodded politely at us and wandered around, his hands clasped behind his back. He had a very odd way of looking at things, as if he were memorizing every detail.

On the door that led into the snug were pinned a collection of drawings and paintings that Mags and I had done when we were little, and the pinstriped policeman stopped to look at them now. He leant in closely to examine six-year-old Mags’s ‘ship sinking in a strom’, and then studied my ‘JIANT SEAMONSTER IN AUTUM SUNSET’.

I stared at the familiar, brightly coloured shape that was bursting out of the blue waves – a misshapen head full of triangle teeth. This war is a sea monster, I thought. Sometimes it destroys things violently and openly, and sometimes its tentacles squeeze in through the cracks of normal life, and it strangles us silently.

The policeman touched one of the pictures, and his mouth twitched as if he were trying not to smile. Perhaps he is kind, I thought, but then he did the dry little fox-cough that I remembered from the courtroom, and asked if one of us could show him up to the lighthouse. Kind or not, he was looking for evidence – something that would prove my Mutti’s guilt. My heart stuttered in my chest.

Pa couldn’t say anything – he looked as if he could barely move. So it was down to me.

‘Watch the first step,’ I said as my trembling hands unbolted the metal door at the foot of the staircase. ‘It’s a bit wonky.’