Mum saved the news that you were dying until the day I moved back to London. She’d got us a takeaway from Raj Mahal, and we were watching The X Factor in the living room of the flat she still called ‘ours’.

​‘I didn’t want to upset you while you were so far away,’ she said.

​On TV, a man gaped in goofy surprise and a woman cried while fanning her eyes, a habit that seemed to have infiltrated popular culture in my absence. A mouthful of dal joined the lump in my throat and slid painfully down to my stomach.

​Mum made the arrangements for me to visit you in the hospice. It was late afternoon, and the sun shone on the waxy expanse of your scalp. My chest constricted when I saw the mottled grey skin on your face. No trace of the rosiness I used to think of as your “apple cheeks”, though I never would’ve told you that; some things you keep from the person who taught you your times tables.

We talked about my ten years away in Berlin, Manila, Taipei and Accra. War in Iraq, earthquakes in Iran and the new Ian McEwan. Anything but why you were lying in a narrow bed looking like an x-ray of yourself.

‘Your mum must be so happy you’re back,’ you said in the wispy voice I could barely believe was yours. ‘What are your plans now you’re home?’

I wondered what Mum had told you: divorced (a German), depressed, no children, never wanted them, never settled though she’s nearly thirty-two, lost touch with her friends. Says all they care about these days is mortgages and IKEA. Only back because you don’t leave a parent alone for too long in our culture.

‘What’s “home”?’ I said, forcing a laugh.

​We talked about Nigella’s molten lava cakes, and then you said, ‘You’ll work it out, Sarah. Don’t be too hard on yourself.’

​The tears that ambushed me were mainly for you. Your stubborn refusal to stop caring. I scratched at my eyes, pretending they were itching.

​After your funeral, as our bus crawled along in the rain, Mum said, ‘Remember when we met her? She seemed so strict. I never thought your teacher would end up being our friend. Miss Clarke …’

​She dabbed her face with the corner of her black headscarf. I held her hand as I leant against the window, disoriented by the combination of the lurching bus, the nostalgic feel of the dry skin on her fingers, the rain drumming on the glass and the hazy glimpse of Tesco’s where you used to drive us every Friday after school, shielding Mum from a flood of words she didn’t understand.

​‘Look, ya Sarah,’ she said, nodding across the road. ‘See the office where you worked that summer? It’s become a sandwich shop.’

​‘Right,’ I said, not looking.

‘What was his name again, your boss? Ellen?’

‘Alan.’

Oh, Alan, with the timorous voice and gentle, anxious eyes. Alan who’d said, ‘The thing about The Muslims, Sarah, is that they’re not like you and me …’

Seconds had ticked by like hours while I’d stared at my nails, wearing a nothing-to-do-with-me expression. Protected by my name that worked in both English and Arabic, and by my short skirt and could’ve-been-many-things face. Then I’d picked up my bag, collected my mug from the tea-point and left without my last week’s pay. Mum never knew. Somehow, it felt like my fault for tricking Alan into thinking I was somebody else.

The bus stopped outside Bishop’s Green junior school. Hard to believe all that Victorian red brick wasn’t luxury flats yet. For no obvious reason, Mum and I started laughing softly in unison.

​‘Remember …?’ she said, and I said, ‘Yes.’

​I remembered moonwalking along the slippery corridor outside your classroom. The smell of plasticine and stale milk and fake-strawberry-scented erasers. The clock Caroline and I broke during an illicit game of catch, and the sandalwood pencil sharpener that reigned supreme on your desk — I’d come up to sniff it.

I remembered how you’d taught words like ‘oxters’ and ‘dander’ to children whose parents couldn’t speak English. How you’d said any girl would be lucky to have the ball of frizz that earned me the nickname ‘Bushbaby’ from my classmates: ‘Your hair stands up because it’s proud of itself, and why shouldn’t it be?’

I remembered the time you told me you liked my drawing of a shipwreck more than my endless portraits of a girl standing alone under an apple tree, because those were too sad: ‘At least the sailors have each other, even if they’ve lost their ship.’ I think that’s when I stopped being scared of your booming voice and thunderous handclaps, and started noticing the golden flecks in your irises and the way they caught the light when you smiled.

​The bus jerked towards the station, splashing past the Kwik Fit, the halal butcher, the pawn shop and the church: watery blobs in a child’s painting of “home.” Clinging to Mum’s hand as if I were drowning, I closed my eyes and remembered how you’d shown us what that word meant years before I asked you.