We sat down as directed. Ava perched next to me on the overstuffed sofa and Mum settled on a manly-looking leather armchair with wings, the kind of seat you could imagine someone snoozing in by the fireside in an old red-curtained library. Ingrid went off to the kitchen to get us drinks, and once she was out of the room we all relaxed a little.

Mum yawned and stretched, and said she was going to have to make a definite effort not to drop off. I could see her point, though I didn’t feel at all sleepy myself: it was rather stuffy in Ingrid’s flat, and the French windows were shut tight.

Ava looked up at the old picture of the couple on the mantelpiece, the one I’d assumed was of Ingrid’s parents. She said, ‘They look like a barrel of laughs, don’t they?’

‘Ava, please,’ Mum said.

Ingrid came back in, carrying a tray which she set down on the coffee table in front of the sofa. ‘Please, don’t let me interrupt. What are you talking about?’

‘Oh, nothing,’ Mum said airily.

‘Then I look forward to joining the conversation,’ Ingrid said, and passed me my ginger-beer.

When I was a bit younger I’d read pretty much every Enid Blyton in the library, and ginger-beer was the kind of thing children in Enid Blyton liked, which was why I had opted to try it. It turned out to be strange and rather disappointing, and I decided I wouldn’t have it again. Ava didn’t have anything. She was good at saying no in circumstances under which it might have been polite to say yes. Mum had water (Ingrid frowned at her request for decaffeinated tea) and Ingrid had a very small sherry, which she sipped rather devoutly, as if all this was as strange and difficult for her as it was for us. Perhaps it was.

Ingrid had taken the most ladylike chair, all padded and pale blue velvet with little matching buttons, the sort of thing you’d expect to find in a boudoir. She was sitting very upright with her legs crossed at the ankles; she had pretty good legs, the kind you don’t expect an old lady to have, and she was wearing black patent high heels with buckles on them. Witch’s shoes, basically.

I tried to catch Ava’s eye – it would have been nice to exchange conspiratorial glances, as if to say, This is something else, isn’t it? But she ignored me. Instead she got her phone out of her pocket and said, ‘Have you got wi-fi?’

The look Ingrid gave her would have frozen a firestorm. She said, ‘Are you in the habit of using your device when visiting long-lost relations?’

Ava blushed – not something I could remember ever seeing before. Then she looked sullen. ‘I just wanted to check my emails,’ she muttered. ‘Anyway, you’re the only long-lost relation I have.’

Ingrid glanced at Mum. ‘But there’s an aunt somewhere, isn’t there? Mark told me you have a sister, Jenny.’