‘God, if we’re the poster kids for a happy relationship then you’re all screwed,’ she says, laughing. ‘Try sharing a bed for more than twenty years with someone who snores like he does. That’s surely grounds for divorce.’

‘If the only complaint you have in all that time is the fact that he snores, then I’m sorry, dear sister, but I have no sympathy for you.’

‘True,’ she says, holding her hands in the air. ‘But he also leaves the milk out, which is a sackable offence, surely?’

We laugh and for a few moments it feels like old times again. Back when I was Vanessa, the successful marketing manager leading a team of five in my plush office in Chelsea, and I would spend my Saturdays catching up with Georgie over a bottle of dry white in the village. That feels like a different planet now, that time, that life.

‘There really is nothing to worry about,’ I tell her. ‘I’ve had a bit of a blip but I’m coming out the other side. I can feel it.’

‘Good,’ says Vanessa, squeezing my arm. ‘It hurts me to see you so low.’

We reach the end of the common and as we stand waiting to cross the road I see something up ahead, a flash of yellow. As we draw closer I see a satchel that looks just like the one I bought Lottie for Christmas a couple of years ago. And then I recognize the tight red curls, the broad shoulders.

‘It’s Lottie,’ I say, quickening my step. ‘Over there by the bookshop, look.’

‘Where? I can’t –’

As she’s speaking, a dark figure springs in between us. In the strobed light it looks like a horned demon.

‘What the hell?’ I scream, staggering backwards.

Then, as the sun disappears behind a cloud, the figure takes form and I hear sniggering.

It’s someone dressed up as a cartoon horse.

‘Sorry to scare you,’ it cries in a cut-glass accent. ‘Just after some spare change. It’s all for a good cause. The folks at the riding school are raising funds to provide new facilities for disabled kids.’

I watch as my sister takes out her purse and places a five-pound note in the collecting tin.

‘Thank you, ladies,’ chirps the horse. ‘Have a lovely day.’

As it departs, Georgie shakes her head and laughs.

‘Are you all right?’ she says, taking my arm. ‘You got an awful shock.’

‘I’m fine,’ I say, feeling rather foolish.

‘I don’t think that was Lottie,’ says Georgie as we head past the bookshop where I thought I’d seen her. ‘She wouldn’t come to Wimbledon without getting in touch to say hi, surely? After all, it was just a silly quarrel.’