The Santiago Sisters. Victoria Fox

then flattened into grassy plains, like the whipping surface of a vast and angry sea.

      ‘What’s Papa doing?’ asked Teresita.

      ‘Nothing. Forget it.’

      But Teresita wouldn’t. She always demanded to know, to find out. She was always asking these dumb questions that Calida didn’t know the answers to.

      ‘I can hear it screaming. Does it hurt?’

      ‘No,’ said Calida, putting an arm round her. ‘Come here.’

      She drew Teresita close. Her sister’s hair smelled of the horses: the rich, solid scent of the saddlebags and the coarse rope of the reins, the leather stirrups, the tangy metal bit they put between Paco’s teeth and heard him crunch on like an apple core.

      The guanaco shrieked a final time. Teresita pushed against her; whether with fear or resistance it was hard to say. Calida had felt her twin’s push from the very beginning: when they were born, a strength driving behind her, indignant at having been left behind. Hurry up, come on, get out, it’s my turn … When she had been old enough to identify it, and recognise in Teresita’s mop of black hair and huge jet eyes the sister she would love until the ends of the earth, Calida sensed that push so often in her life. Teresita’s struggle when she was crying and didn’t want to be comforted; her wishful gaze, reaching beyond the perimeter of the farm and into the frightening unknown; her resentment of gravity when all she longed to do was fly. Calida stayed on the ground, arms out, ready to catch her if she fell.

      But there was a pull, too; a force of belonging that could never be changed and never be dimmed. It was blood, a mirror heartbeat, a laugh that echoed her own. At night, when they lay in their bunks, giggling in the dark or making hand shadows on the wall, whispering secrets that didn’t need to be told because they already belonged in each other’s hearts, Calida knew that this connection was a rare and precious gem. Faith. Trust. Devotion. Loyalty. No matter what, the sisters were there for each other.

      ‘What’s going to happen when we’re grown up?’ said Teresita now.

      ‘I don’t know. I haven’t thought about it.’

      ‘Mama says not to do what she did.’

      Calida didn’t reply. Instead, she said: ‘We’ll be together, though, won’t we? So it doesn’t matter. We’ll always be together, you and me. Promise?’

      Teresita ran a hand across the brittle earth. She blinked against the sun, and gave Calida a smile that warmed her bones. ‘Promise. Can we go back yet?’

      Calida went up the ridge to check. Diego was untying the horses. The guanaco was gone and she saw the slash of blood on her papa’s bombachas and dared herself not to look away, to be the big girl Diego always told her she was.

      Paco chewed lazily on a tuft of yellow grass.

      ‘Come on, then,’ said Calida.

      Every day the sisters went riding with their father, while Julia stayed at home. It had been that way since time began. Their mother rarely emerged and the girls knew not to make noise in that part of the ranch, especially when Julia was resting.

      Calida tried not to feel sad at how, on Julia’s better days, she would invite Teresita into her bedroom; Calida would listen at the door, shut out of their exchange, desperate to hear and be part of the confidence, until she heard her papa’s tread and shame directed her away. Julia spent hours brushing Teresita’s ebony hair and singing her songs, telling her stories of the past and stories of the future, assuring her what a magical woman she was destined to become. Her mama adored Teresita, because Teresita was beautiful. The twins’ division was responsible for this injustice, marking their physical difference: Teresita as exquisite and Calida as average. Calida knew there were greater things in life than beauty, but still it hurt. She wasn’t special, or in any way extraordinary, like her sister. If she were, her mama would love her more.

      Once upon a time, when Julia had first been married, she herself had been a magical woman. Calida had seen the evidence, photographs her father had taken when they had worked the land as a couple: Julia against the melting orange sunset, her head turned gently away and her hair in a thick plait down her back. The horse’s tail had been frozen in time, a blur when it had swished away flies. Calida loved those pictures. This was a woman she had never known. She longed to ask her mama about that time, and what was so different now, but she was afraid of making Julia angry.

      Julia told Teresita those things, anyway. At least she was telling someone.

      Summer 1995 was unbreakingly hot. Sunshine spilled through open doors, the heat bouncing off wood-panelled walls. The twins were in the kitchen, paper pads balanced on their knees. Their home tutor was a harsh-looking woman called Señorita Gonzalez. Gonzalez was thirty-something, which seemed ancient, and the way she wore her hair all scraped back from a high forehead and her glasses on the end of her nose only made her more alarming. She wore heavy black boots whose tops didn’t quite reach the hem of her sludge-coloured skirt, so that a thin strip of leg could be seen in between. In classes, Teresita would giggle at the black hairs they spied lurking there, and Calida had to tell her to shut up before they got told off. Gonzalez was strict, and wasn’t afraid to use their father’s riding switch if the occasion arose.

      ‘I’m hot,’ said Teresita, kicking the floor in that way she knew drove Señorita Gonzalez mad. Calida’s own legs were stuck to the wooden chair, and when she adjusted position the skin peeled away with a damp, thick sound.

      ‘Díos mio, cállate!’ hawked Gonzalez, scribbling on the board. ‘All you do is moan, Teresa!’ It was only the family who called her Teresita: it meant ‘little Teresa’.

      Teresita stuck her tongue out. Since the teacher’s back was turned, this failed to have the desired effect, so she tore off a sheet of paper, balled it up and tossed it at Gonzalez, nudging Calida as she did so, to include her in the game. But Calida didn’t like to stir up trouble. The woman froze. Calida gripped the seat of her chair.

      ‘You little—!’ Gonzalez stormed, blazing down the kitchen towards them, whereupon she grabbed Teresita’s hair and hauled her up, making her scream.

      ‘Ow! Ow!’

      ‘Stop it!’ Calida begged. ‘You’re hurting her!’

      ‘I’ll show you what hurts, you disrespectful child!’

      Gonzalez dragged Teresita up to the cast-iron stove and launched her across the top of it. ‘That hot enough for you?’ she spat. Calida felt the impact as sorely as if she were the one being assaulted: Teresita’s pain was her pain. But her sister stayed silent, contained, her dark eyes hard as jewels and the only giveaway to her panic the lock of black hair that hovered next to her parted lips, blown away then in, away then in, flickering with every breath. Gonzalez took the riding switch from behind her desk and drew it sharply into the air. ‘Time for a lesson you’ll really remember!’

      ‘Wait!’ Calida leaped up. ‘It was me. I threw the paper. It was me.’

      There was a moment of silence. Gonzalez looked between the twins. Calida rushed to her sister’s side and shielded her, just as the kitchen door opened.

      ‘What is going on in here?’

      Diego stood, his arms folded, surveying the scene. Calida felt Teresita squirm free, but not before she took Calida’s fingers in her own and squeezed them tight.

      ‘The girls fell down …’ Gonzalez explained, in a different voice to the one she used with them: softer, sweeter, with an edge of something Calida was too young to classify but that seemed to promise a favour, or a reward. ‘You know how energetic they are, rushing about … Honestly, Señor, I have my back turned for one minute!’

      Diego approached and ruffled Calida’s hair. ‘There, there, chica.’

      Calida clung to her father. She inhaled his warm soil scent. Diego held his other arm out to Teresita, but Teresita watched him and stayed where