And I took her by the hand and led her to her bedroom, settled her into bed with an army of soft toys, then went back to my own room. Within minutes I was asleep, but at half past two Gaia’s shrieks ripped through the house. I staggered quickly to her room, expecting to find it full of bats or giant spiders, and when I found neither I tried to console Gaia with a glass of water. She held my hand in a vice-like grip, and when I woke again – once more to the sound of screaming – I was on the wooden floor beside Gaia’s bed, huddled beneath a blanket. Again, I settled her to sleep by stroking her face and holding her hand, and this time she said, ‘I love you, Mumma’ between tear-stricken gasps. I was exhausted, but my heart broke for her.

This went on every night, with a side order of Coco waking every couple of hours. Coco didn’t shriek, though. She was sturdier than Gaia, both in build and temperament, her shining round cheeks always lifted in a gleeful smile. She was quite a heartening child to be around. At night, she babbled and bounced in her cot until I found that a warm bottle of milk persuaded her to lie down and quietly mull over the idea of sleep.

One night, when I’d put Gaia back into her bed for the millionth time and fallen asleep beside her, I was woken not by screaming, but by a question.

‘Sophie?’

‘Hmmm? What?’

‘Are you going to die?’

‘What?’

‘Are you going to die?’

‘Die? Uh, no, Gaia. Not at the moment. I’m too tired.’

‘What about tomorrow?’

‘Why are you so worried about me dying, Gaia?’

She was sitting up in bed, her hair a fuzzy cloud and her glasses askew on her face. Her pyjamas – navy with a snowdrop print – were buttoned wrongly, and Louis was sitting at her feet. She bounced my question around her mind.

‘Mumma died,’ she said softly, and my heart expanded to the size of a football pitch. I wrapped my arm around her.

‘I know she did. I’m so, so sorry. I bet she loved you lots and lots.’

I thought of what Maren had said about their mother. Suicide. How awful. The party line is that Mummy had an accident. How long could they really expect to keep up that pretence? I wondered. Gaia was a very perceptive child, visibly possessed of that firstborn curse of wisdom beyond her years. If her mum died by suicide there would have been signs. Gaia would have known something was wrong.

Gaia buried her face in my side and wrapped her arms and legs around me, so tightly I thought I would be left with bruises. She caught one of the scars on my right arm with her wrist and I yelped in pain.

‘What’s wrong?’ she whispered, panicked.