‘I’m sorry,’ she said in a voice so tiny that if I hadn’t seen her lips move I wouldn’t have heard. ‘I was going to tell you, but then when we got so close I was scared in case it spoiled everything. And I wasn’t sure, not at first. But then, when you were telling me about your dad . . . Well, you could have been talking about mine. And that story about trapping his finger in the cupboard. That was Dad all over. I could just imagine it happening exactly as you told me. You know that he played the violin? That was his job – with us, that is.’

I shook my head. This wasn’t right. How could my dad have played the violin professionally and me not even know that he was musical? I was starting to feel woozy with it all.

But then it was Hector’s turn to look confused. He snapped his head round to speak to Clio. ‘But how do you know her?’ he asked, pointing a finger at me. He leant on the word ‘her’ as if I was something stuck to the bottom of his shoe.

Clio smiled at me and then she slipped her arm quietly round my waist and pulled me in closer to her. Her citrusy perfume smelt fresh and clean.

‘Leah? She has a name, Hector. Well, I came to the house when Dad died. Like you, I remembered that day trip and when I found the address in Dad’s notebook, I just knocked on the door and asked if I could have a look round for old times’ sake. Leah let me in and was kind to me and we just went from there. She is the nicest, funniest, most thoughtful friend I have ever had and I couldn’t be prouder or more delighted that she is also my sister.’

The beginnings of an anger that had been building inside me just evaporated as I realised that I felt exactly the same way about Clio. I wasn’t sure I understood why she hadn’t told me what she knew, but it didn’t make one iota of difference to our relationship. In fact, us being sisters was just the cherry on the cake. I grinned at Clio and was pleased to see the relief that flooded her face as she realised that I’d forgiven her.

This was all starting to feel a bit like the end of an Agatha Christie novel as I slowly slotted the pieces into place. Did it mean that Dad was dead, then? I supposed that it must do. He’d been as good as dead to me for years anyway, but it was still a shock to think of it. I couldn’t deal with that part just yet, but I didn’t have to, because Clio hadn’t finished.

‘But how do you know Leah, Mum?’ she asked.