In the next town over, a man had killed his family. He'd nailed the doors shut so they couldn't get out; the neighbours heard them running through the rooms, screaming for mercy. When he had finished he turned the gun on himself.

Everyone was talking about it — about what kind of man could do such a thing, about the secrets he must have had. Rumours swirled about affairs, addiction, hidden files on his computer.

Elaine just said she was surprised it didn't happen more often. She thrust her thumbs through the belt loops of her jeans and looked down the dreary main street of their town. I mean, she said, it's something to do.

Cass and Elaine first met in Chemistry class, when Elaine poured iodine on Cass's eczema during an experiment. It was an accident; she'd cried more than Cass did, and insisted on going with her to the nurse. They'd been friends ever since. Every morning Cass called to Elaine's house and they walked to school together. At lunchtime, they rolled up their long skirts and wandered around the supermarket, listening to music from Elaine's phone, eating croissants from the bakery section that were gone by the time they got to the checkout. In the evening, they went to each other's houses to study.

Cass felt she'd known Elaine for ever; it made no sense that they had not always been friends. Their lives were so similar it was almost eerie. Both girls came from well-known families in town: Cass's father, Dickie, owned the local Volkswagen dealership, while Elaine's dad, Big Mike, was a businessman and cattle farmer. Both girls were of slightly above-average height; both were bright, in fact they were consistently at the top of their class. Both intended to leave here someday and never come back.

Elaine had golden hair, green eyes, a perfect figure. When she bought clothes online, they always fitted perfectly, as if they'd been made with her in mind. Writing about her in her journal, Cass used words like grace and style. She had what the French call je ne sans quoi. Even when she was clipping her toenails, she looked like she was eating a peach.

When Cass came round to Elaine's house, they would sit in her bedroom with the carousel lamp on and look at the Miss Universe Ireland website. Elaine was thinking seriously about entering, though not for the title itself so much as the opportunities it might offer. The previous year's winner was now brand ambassador for a juice company.

Cass thought Elaine was prettier than any of the contestants pictured online. But it was tricky. Each of the girls competing to be Miss Universe Ireland, and from there to be Miss Universe for the world/universe overall, had an adversary they had overcome. One had been a refugee from a war in Africa. Another had needed surgery when she was a small girl. A very thin contestant had once been fat. The adversary had to be something bad, like a learning disability, but not really bad, like being chained up in a basement for ten years by a paedophile. Cass's eczema would be a perfect adversary; they wondered, if she held her skin up against Elaine's long enough, whether she could pass it on to her. But it didn't seem to work. Elaine said the adversary requirement was unfair.

When you think about it, it's almost like a kind of discrimination, she said.