From the day Sissy fights a boy in the playground in front of Tegan, they realise they are not like the other girls. Both raised in unusual families, they become so close they feel like one being, wrapped around each other in bed at sleepovers, sending photographs to men they meet online, scaring each other with reports of the girls being snatched at night in their town. But as their rituals push against the boundaries not only of childhood, but of possibility, Sissy feels herself transforming into something strange and terrifying.