Michael had thought she was me, assumed I was nervous and that was why I wasn’t quite “myself.” But as he had turned to look at me in the doorway of the room, dressed in the uniform I wore to wait tables and serve drinks, with my name badge as clear as day pinned to my blouse, I witnessed the light of his love die immediately as shame and anger and a whole host of things I’ve never been able to describe crossed his face in an exquisite moment of pain and betrayal. He had pulled his clothes back on and run. Leah had sat up, letting the duvet fall away to show her nakedness. She looked me in the eye—“He wasn’t worth it, Sis”—tossing her hair back and laughing to herself. The anger boiled hot and bright. Luckily for her, Mum had come home early and had dragged me off my sister. We had both been grounded, Leah for putting out and me for planning to. For two weeks we weren’t allowed to leave our room as we considered our morality. My anger cooled and my desire to kill her abated, and I had begun to plan how I would get away from the girl who would stop at nothing to take everything from me.

Well, she wasn’t going to take Chris. Even if I wasn’t sure I wanted him anymore.

I can’t stop looking at the picture on her Instagram. The picture in the slutty dress with her blue bra on show was taken on the pristine steps of her home. I recognize it from the pictures featured in an edition of Writing Magazine four years ago, after she had celebrated twenty weeks on the Sunday Times bestseller list by buying an overpriced white stucco property in fashionable Belsize Park. An area filled with attractive women in Lycra, holding personalized eco-friendly coffee cups as they strolled toward their Bikram yoga class. Or was it aerial that was trending now? No doubt Leah would be into it, whatever it was. The article, entitled “How the other half live,” showcased the excessive wealth of the handful of authors who had hit it big in the last few years. Leah’s house was valued at around two million pounds. Almost seven times the pokey little maisonette I had scrimped to buy, burdened with a huge mortgage and sense that something major was about to go wrong, like the ceiling caving in, or the water tank spontaneously bursting. Leah had paid cash and her place was in perfect condition. The article was published three days before Chris suggested we move in together, pool resources to buy something nicer. I had jumped at the chance.

The book Leah wrote was an exposé about our lives growing up as twins. The book we had promised we would write together. It was going to be the way we mended things between us. I had quit my job and we hunkered down in a cottage in the middle of nowhere for the winter: writing all day; drinking all night; existing on a diet of baked beans and the occasional roast dinner served in the local pub. But the money we had saved for this adventure ran out faster than we had thought. And so I reluctantly went to find a job, leaving Leah in that little cottage to put the final touches to the manuscript and begin to woo an agent. But as I worked my arse off doing the accounts for a lumber company in Reading, living in a damp houseshare so I could keep up the rent on the cottage and send Leah care packages, she had a different plan. Instead she wrote the story we had promised not to tell, took my name off the project and sold it solo. She made millions from the book. Stories of identical twin antics and the double life my father had lived had broad appeal.