Sometimes I pretend she’s a movie star and that she notices me and tells me I’m destined to be a star, too. Other times, she is a fashion icon impressed by my designs and we walk the boards together in our fine outfits and colourful hats.

In reality, usually Mrs Grunberg just winks at me and laughs as she squeezes my cheeks and I run back to the boys.

But Mrs Stewart – she has something on top of all that. Is it that her clothes are even brighter? Or that she laughs even harder? Whatever it is, I can’t stop watching her.

She is so different from my own dear Mutti. My mother only ever seems to wear grey nowadays. At least, if I picture her, that’s what I see. Grey or black. She doesn’t wear any colour. She used to. Not like Mrs Stewart or Mrs Grunberg, even. More like the other women in this carriage with their suits and hats and nice shoes. But now: only grey and black. And her eyes are dark to match her clothes.

Yesterday I overheard her and Vati – my father – talking in low voices in the kitchen. I was on the landing, crouched down behind the banister so I could hear them without being noticed.

‘You look like you’re in mourning,’ Vati said.

‘Maybe I am,’ Mutti replied.

‘Who for?’ Vati asked.

There was a long pause after that. I strained to listen and eventually I heard Mutti say, ‘For all of us.’

I didn’t know what she meant by that, but they didn’t speak again for a bit. I went downstairs a few moments later. Mutti and Vati were sitting at the table. Vati had his hand over Mutti’s. She looked across when she saw me come in, then she quickly got up and went to the sink. As she passed me, I could see that her eyes were wet. I followed her to the sink and put my arms around her waist. ‘Are you all right, Mutti?’

She gripped my hands and squeezed them so hard it hurt a bit. Then she turned round, wiped her eyes and ruffled my hair. ‘I’m fine, darling,’ she said. ‘Now go and tell your brother it’s dinner time.’

That meant: don’t ask any more questions. It’s like that all the time at home lately. Overheard snippets of conversations between my parents that I don’t understand and that clearly neither of them wants to talk about to me or Otto. Otto is my brother. He’s two years older than me and after Leo and Max he’s my favourite boy in the world.