‘Rachel,’ Sophie said, the syllables slurred, a hand held over her mouth in shock. ‘Rachel!’ she repeated, stumbling to her feet and coming over to envelop me in a tipsy hug. ‘Come and have – I dunno, a glass of water. Girls, budge up for my sister.’

It was almost impossible not to break down. I hugged her back fiercely. ‘Sophie, I need to talk to you,’ I said into her hair, wrapped tight enough to smell the serum from her party-ready blow dry. ‘I really don’t want to ruin your night, but can we go outside? It won’t take long.’

Sophie’s smaller than me: she looked up at me, her eyes round with confusion. She’d pushed the boat out, worn contact lenses instead of her familiar wire-framed glasses. ‘But – can’t we just have a nice time?’ she pleaded. ‘Is it illegal for me to say I’m so happy you’re here?’ She giggled, hugging me tighter. ‘I’m sorry, I’m not taking the piss. It’s just so nice to be normal.’

‘Course we can, but only once we’ve had five minutes on our own.’

I preferred my old lies – the selfish, addict variety which were only about pleasing myself. This lie was so painful that it nearly broke me.

We stood at the bottom of the spiral staircase, dodging the few smokers who were brave enough to puff their way through the freezing February night.

‘Rachel…’ she said, swaying on the stilts of her high heels, a goofy grin on her face.

I couldn’t lose focus. I’d rehearsed this in the mirror, but having her with me made it so much harder.

‘Sophie, I love you…’

‘I know that, silly!’ she said, grabbing my hand, her words still slurry. ‘Can we get a drink now? Sorry… that was in… insensitive.’

‘Don’t worry about that now,’ I said, holding her arms and looking into her soft, pretty face. ‘I’m going away for a little bit. There’s a big project in Scotland that they’re putting me on to, and I’m leaving this weekend.’

‘That’s great!’ she said, face lighting up. ‘So it’s going better again? You seem better, Rachel.’

Lying to her was like a knife in my own ribs: I hated and treasured how much my successes were her successes. Her face in that second was another treasure for my memory box.

‘Yeah, yeah it is,’ I said. ‘And I am. But I need to tell you a couple of things before I go.’

I watched her bubbliness drain away. ‘What are the couple of things?’ she asked uncertainly.

This was agony.

‘Firstly, how lucky Toby is and how much I hope you’ll be really happy.’

‘But – you can come to the wedding?’

I kept going.