I was standing by the window looking at the weedy front drive below, my view distorted by a maze of raindrops. I felt sorry for the beech trees and the old yew languishing under the torrent, branches drooping with the weight of water. The smoky sky was empty of birds. The distant fells wiped out in a haze of cloud.

  Henry stood up. ‘Hey, Alice, Cilly, come here,’ he ordered. I cast him a sour look which he ignored. All my life, my siblings had given me the nickname. To everyone else’s ears it sounded like ‘Silly.’ I was certain that’s why they used it; they didn’t think I was as clever or quick-thinking as them. ‘Did you know that if you put one hand over one half of your face and then the other,’ he was saying, ‘you can tell which half is good, and which is evil?’

  I took a step towards him, interested despite myself. With the air of a conjurer about to perform a trick, he placed his right palm over the right side of his face.

  Alice pointed. ‘Your left side’s crooked,’ she laughed. ‘Maybe God went off for his lunch when it came to making that bit of you.’

  ‘Alice!’ I worried that one day she would be struck down. God peering through our window at the wrong moment and catching her out in her blasphemy.

  Henry, older than us by two years, stared at himself in the small mirror on his wall. ‘No, you dolt. This is my evil side.’ He turned and leered at us, clawing his hands. ‘Now you,’ he said, sitting on his bed. ‘Do it at the same time. Maybe your sides will be different from each other? You know, like a mirror?’

  We stood side by side, covering the left half of our faces with our left hands, switching to our right. Then we covered opposite sides. I sniffed longingly at the memory of breakfast toast on my fingers as I submitted to Henry’s scrutiny.

  ‘It’s strange,’ he said, narrowing his eyes to squint at us. ‘I can’t tell which side is which on either of you.’

  We jostled for space in front of Henry’s wall mirror and tried it again. My eyes flicked from my face to Alice’s. The same high forehead, one black swooping brow over a hazel eye. Half a straight, slightly long nose with a flared nostril. Half a small, rosebud mouth.

  ‘One of you must be all good and the other all evil.’ Henry’s voice came from behind us. ‘And I bet Alice is the wicked one.’

  ‘Oh, ha, ha,’ Alice said, swinging around. ‘Quick, Cilly, grab his legs!’ she shouted as she rushed him.

  Henry let out an oomph as Alice took a leap and crashed into him, sending them both sprawling across the bed. There was a struggle, but she managed to get the upper hand as she knelt over him, her dark hair flopping across her face, ragged ends like a witch’s mane. He laughed and writhed, fighting back, grabbing her wrists. She shrieked and tried to jerk away, but he hung on, his older-brother-strength winning. ‘I knew you were the Devil’s child!’ he gasped, laughing as he tipped her off him.

  I looked at their thrashing legs and wild-eyed mirth, and then the door. Daddy’s study was only on the floor below. He was probably working on his manuscript – his great work – a time he must never be disturbed. I shushed them in an urgent mime, finger to my lips.

  Ignoring me, Henry sat up, rubbing his stomach. ‘You should play rugby,’ he told Alice, ruefully, as he flexed his hands. ‘Think you broke one of my fingers.’

  ‘Cilly!’ Alice was rubbing her wrist with a wince where Henry’s grip had squeezed red marks. ‘Why didn’t you help me?’

  I was remembering our two faces in the mirror – two halves of a whole.

  ‘Earth to Cilly?’ Alice pushed the tangle of hair out of her eyes. ‘Perhaps you’ve been turned to salt,’ she said sarcastically. ‘Like Lot’s wife?’

  ‘Or stone, like one of the animals in The Lion, the Witch and the Wardrobe after the White Witch has gone by.’ Henry suggested.

  ‘Get her!’ Alice shouted, jumping off the bed. ‘Tickling will break the spell!’

  I was standing nearest to the door and let out a squeal as I made a run for it. The other two charged after me, and faster than all of us, the stable cat, a streak of bone and muscle, off down the long, damp corridor with its tail straight out behind.

  3

  ALICE

  I check my reflection in the mirror before I go downstairs and my sister stares back. I have her latest photograph to remind me that now I’ve had my hair cut, the differences between us are still tiny, and without the other for comparison, unlikely to be noticed. I have a freckle high up on my right cheek, and she has the same one but on her left side; she also has a tiny scar shaped like a nail pairing on her chin. Her bottom lip is plumper than mine. My nose is a little shorter. Our eyes have the same halo of yellow filigree, a starburst around our pupils. The only difference is she has a blemish inside her left eye, the legacy of a childhood accident with a sharp stick. But to see it someone would have to be gazing intently into her iris.

  All I need is confidence. If I pass the first impressions test, then perhaps they won’t get suspicious when my cooking tastes terrible, or when their washing comes out purple or several sizes smaller. Cecily seems to have turned herself into a domestic goddess, whereas I can’t cut a slice of bread straight. I take a deep breath. Here goes.

  At the bottom of the stairs, in the narrow entrance hall, I hear the fridge closing, the scrape of chair legs against the floor. I approach the kitchen, and see a figure hunched over the pine table.

  ‘Bea,’ I exclaim, despite myself.

  A dark-haired girl raises her head, glancing through a greasy fringe in my direction. There’s a smear of purple on her top lip. She clasps a hefty white sandwich with both hands, butter and what looks like jam oozing from the middle. She grunts a brief greeting and returns to her sandwich. She has a glass of milk next to her elbow and the cat is sprawled, purring, on her lap.

  ‘Everything okay? You’re home early… aren’t you?’ I take an awkward step closer. ‘You’re hungry?’ I say, thinking I could offer to cook; that would be the maternal thing to do, wouldn’t it? An omelette, perhaps. Something quick and easy.

  ‘Yes, I’m hungry,’ Bea snaps. ‘So what? God. Can’t you just leave me alone!’ and she gathers up her plate and glass and stalks past me out of the room. I hear her thumping up the stairs. Having slithered from Bea’s lap, the cat licks at her back leg with earnest attention.

  I sink into the chair Bea’s just left. There are drops of milk and crumbs on the table, a sticky jar of cherry jam with the lid left off. I let out a long breath. ‘Damn,’ I say quietly.

  I have the achy hollow pain of homesickness, although there’s nothing for me to miss. I have shaped my life purposely to avoid belonging in one place. I haven’t settled anywhere since leaving Hawksmoor. Perhaps it’s just the tension of pretending. I rub my eyes, remembering too late about the bloody mascara. I told Cecily I’d do this for a week, but suddenly seven days feels impossible. I could leave right now – it would be easy to walk away, catch the next train out of Exeter. I’ve spent the last seventeen years running away. It’s a habit that’s hard to break. To stop myself, I consult the little black notebook she left for me. Her instructions are to cook supper, and I read the list of meals she’s helpfully included: sausages and mash; chops with peas; shepherd’s pie; macaroni and cheese. I frown. She’s still cooking food from our childhood. Mostly meat-based, and me a vegetarian. I went veggie years ago at the kibbutz. I forgot to remind her.

  I manage to find the ingredients for shepherd’s pie and follow Cecily’s instructions. There’s a lot of chopping, and I’m forced to use several pans. As I wait for it to cook in the oven, the oddness of the situation hits me, the reality of being in my sister’s home, the craziness of taking her place. My hands tremble and I have an overwhelming need to get out – to go far away, where I have no responsibilities, where there are no expectations to meet, and no pretence to keep up. The kitchen spins, and I sink into a chair. I focus on breathing, in for four counts, out for four counts. I’m here. Nothing bad has happened. I can do this.

  I go upstairs and knock at Bea’s door. ‘Supper’s ready,’ I speak through the wood in what I hope is a cheerful voice. No answer. I listen. There’s a beat of music. ‘Bea?’ I call louder. ‘Aren’t you going to eat something?’

  Bea doesn’t open the door. ‘Go away.’

  I want to tell her that I’ve spent hours cooking something I can’t eat, and I’ve only just managed to clean the mashed potatoes off the pan. I want to tell her that it’s taking every ounce of courage just to be here. But she can’t know that, and if I’m speaking as her mum, I should probably go on about the importance of protein and vitamins. I hesitate, my hand hovering over her door handle. I don’t know how far to take this – should I order her to come down?

  I decide to leave Bea to her strop. Downstairs, I lean against the kitchen counter, spooning hot potato into my mouth, trying to avoid the mince. Some of it looks a bit pink. Could uncooked beef cause salmonella? I decide not. I pick at oily salad leaves. I suppose I should wait for Gabriel before I sit down to eat. There’s an open bottle of white in the fridge and I pour myself a glass. Every sound makes me cast anxious glances towards the front door. By nine o’clock, I think it would be reasonable to go to bed.

  I cover the dish with a tea towel and go up to the bathroom, splashing my face, using Cecily’s toothbrush from her wash bag to do my teeth. I skip her long-winded beauty routine. Just this once, I think.

  She hasn’t left me a note with her contact details. I’ve searched her room and the kitchen, the two places she might have put an envelope for me. She’s normally so thorough and organised; she’s left me diagrams of the house and area, lists of chores, and realms of notes on how I should behave, even a map of the town with useful places marked with crosses, so it’s strange she’s forgotten a detail like her own address. I’m guessing she’ll send it to me, or she’ll ring when she knows the others will be out. I try not to panic. I’m sure she’ll contact me soon.

  I pick up the hardback book on the nightstand for something to do, flicking through the first pages. It’s a non-fiction tome about the Borgias and despite all the poisonings and betrayals, it makes for dry reading. I learn that cantarella was their poison of choice, probably a compound of arsenic. When it was sprinkled on food and drink, the victim died slowly, growing confused and weak over a period of days. Nice. I try to concentrate on the words, but I’m too tense and I don’t want to read about long-ago murders. At last, I hear the front door open and close. I switch off the bedside light and pull the cover up to my chin. I try to decode the movements from downstairs. Are they the footsteps of a drunk? I listen to him coming up the stairs, hear taps running next door. The wall between my bedroom and the bathroom is thin. It feels too intimate. I’m lying so close that I can hear him gargling and spitting, and then the sound of piss drilling into the toilet bowl. I shut my eyes, as if that will block out the images that spool, unwanted, through my mind. A chain flushes. Pipes gurgle in the wall cavities. I hear him come out of the bathroom and walk past my door. A floorboard creaks. I hold my breath.

  ‘Cecily?’ comes a loud whisper.

  I keep completely still. My heart batters at my ribs. The footsteps move on, up the stairs, and across the ceiling.

  4

  CECILY

  I’d prayed for the miracle of Alice’s return. And just to be sure, I’d sent her a letter complaining about Gabriel and his drinking. It wasn’t exactly a fib. I’d just exaggerated it, explaining how desperately I wanted to leave him, but that I had no time that wasn’t monitored by him. I admit that bit was a white lie. Then I mentioned the word ‘divorce’. It worked better than I could have hoped, because she’d suggested the plan straight away, in fact she’d insisted on the swap.

  She’d written,

  Please let me do this. When we swapped identities as kids, we fooled everyone, remember? I know he’s your husband, but if you’re not sleeping together and barely speaking, I think I could get away with it. Especially if he doesn’t know of my existence. How could anyone who looks so like you not be you? Send me an up-to-date photo of yourself and I’ll get my hair cut like yours, get my nails done. You know I haven’t set foot in the UK since I left – I guess we all deal with trauma differently – but knowing you need me, knowing I can finally do something to make up for what I did will help me find the strength to come back.

  I want to help you break free. Let me give you some time to yourself, so you can have the opportunity to see a solicitor, look for a job, get started on planning a new life before you tell Gabriel you’re leaving him. But the main thing is, by divorcing your husband, you’ll be standing up to our father at last. He’s controlled you for too long. I wish you could see it. He’s a monster, Cecily. Once you’ve done this, we can be together again. You know we belong in each other’s lives.

  On my last day at home, I woke up alert and jittery. The feeling stayed with me as I crossed the carpet to open the curtains, tugging the fabric back and staring down at the large privet hedge that guards our tiny scrap of front garden. Goodbye hedge, I thought. Goodbye street. Goodbye seagulls. With any luck, I won’t see any of you for a long time.

  In the kitchen, Bea was slumped over her breakfast, the cat draped across her lap. ‘Morning, darling,’ I said as cheerfully as I could, pouring myself a cup of treacly darkness.

  Gabriel was there too, buttering toast at the table. He smothered it in marmalade, and bit into it, waving it towards me, ‘You should have some.’ He chewed and swallowed. ‘Carbohydrates are good for hangovers.’

  I scowled at him. He knew perfectly well I didn’t eat in the morning. I picked an apple out of the fruit bowl and crunched noisily through waxy skin into papery flesh. There, I thought. Happy now?

  I kept munching determinedly, the atmosphere sharp as a knife. I had a shred of peel caught in my teeth and as I picked it out, I remembered an experiment I’d heard about, where two apples were placed in jam jars, and for two weeks one apple was told every day that it was loved, and the other that it was hated. The hated one withered faster, slumping into its rotten heart.

  ‘Have you got plans for today?’ Gabriel continued, forcing our stilted conversation, for the sake of Bea, I supposed.

  Our eyes met by mistake and slid away. I shook my head. ‘Nothing exciting.’

  Bea’s hand stilled against the cat as she looked up, glancing between me and her father, an anxious furrow between her brows. Milk moistened her top lip in a pale moustache.

  ‘You have some…’ I gestured to my own top lip.

  Bea blushed and dragged a hand across her mouth. My gaze skimmed her waist. Bea tugged her top down and scraped the last drops of milk from her bowl. My daughter doesn’t feel good enough and I understand that feeling well enough myself. Yet, I’ve never been able to find a way of explaining this to her. Instead, I discovered chocolate wrappers hidden under her bed and threw them in the bin with a sense of having failed.

  Gabriel finished his toast and marmalade in two bites, gathered his battered leather satchel, and began the hunt for his keys, playing the part of the forgetful professor with his mop of curls falling into his eyes, haphazardly lurching through the humdrum necessities of life. I’d turned my back unable to watch, loading plates into the dishwasher, but Gabriel approached as if for a goodbye kiss, and I couldn’t stop myself from flinching. The wounds under my nightdress hadn’t healed. My skin was sore, crusted with dried blood. He saw my expression, and hesitated, frowning.

  ‘Come on, Bea,’ he said in his hearty voice. ‘Let’s leave your mother in peace.’

  ‘Goodbye, darling,’ I called after her. ‘Have a good day.’ Too little, too late.

  It’s strange to think all of that happened yesterday morning, and in the afternoon, Bea came home to Alice. But my daughter doesn’t look me straight in the eye any more, and Alice will have slipped seamlessly into my shoes. It hurts to think that Bea won’t even notice. It hurts that she doesn’t understand how much I love her.

  It’s nearly dawn, and the sky is streaked with red, the distant castle a black wound on the horizon. I shiver and wrap my arms around myself. I’m not dressed for the dank early morning air. It’s just me and some foxes in an empty street, but I shouldn’t be here, standing outside our house. It’s tempting to linger for longer, to watch for the stirrings of activity, the morning routine beginning, just to check that my life is continuing without me. And I have a yearning to glimpse my sister through a window or an open doorway. But the curtains are closed, and the privet hedge blocks the view of the door, and anyway, the whole point of this charade is to slip away unnoticed. It’s what I prayed for. And if this is going to work, Alice can’t know how close I am. She’ll soon discover the real reason I need her to take my place. All I can do is hope that when the time comes, she’ll understand.

  5

  ALICE

  I wake with a jolt, as if someone is standing over me. It takes me a split second to remember where I am. I should have set an alarm. Cecily said to get up around eight. I grab the clock on the bedside table to check the time. Seven thirty. I flop back onto the pillow. Above my head, Cecily’s crucifix is impaled to the wall.

  Two strangers wait for me downstairs. I might look exactly like my twin, but I’m not her. We no longer share a life. In the past, our mannerisms mirrored each other’s. But over the years I’ll have developed gestures and facial expressions that are different from hers. Won’t they guess straight away?

  I abandoned Cecily once. Left her alone with our father. I didn’t try hard enough to save her from him and Hawksmoor. This is my chance to make it right.

  Pipes gurgle in wall cavities, there’s a muted sound of activity coming from other rooms, a rustling outside on the landing, and the sudden clumping of someone going downstairs. I hold my breath, listening. I get out of bed and root around in Cecily’s top drawer, my hiding place for her little black book. The familiar neat, cramped script of my sister’s writing is comforting: