Behind a Locked Door

by Sarah A. Denzil

Genres: Domestic Thrillers; Psychological Thrillers

Synopsis

She opened the wrong door. Now her life will never be the same.

When Lucy Foster visits her old friend, she doesn't expect to hear a baby crying behind a locked cellar door. But what she finds shatters everything she thought she knew: a terrified teenage girl and a newborn, hidden away like a secret shame.

As Lucy's quiet life spirals into a media frenzy, and the town turns against her, one thing becomes clear—someone is watching. And they want Lucy to stop helping the girl in the cellar.

Because the truth is darker than anyone imagines. And unlocking it may cost Lucy everything.

A gripping psychological thriller packed with secrets, lies, and jaw-dropping twists, Behind a Locked Door is perfect for fans of Freida McFadden, Lisa Jewell, and Shalini Boland.

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Release date: September 4, 2025

Print pages: 336

Sample

Chapter One

Bodies are strewn everywhere, sprawled over the wild grass, their limbs stretched out and
their mouths gaping open. I gingerly pick my way through, careful not to step on a pale finger
or twisted arm. My eyes roam across the scene, but I don’t spot the face I want to see. Cool
morning air chills my lungs and makes the hair on the back of my neck stand up.
The barn lies ahead, standing sentinel at the top of a shallow hill that overlooks the
stretches of emerald fields beyond. I turn back for a second and see a pony in a nearby
paddock idly chewing grass.
I shake my head and make my way to the barn. Quiet music throbs through the air
with a pounding bassline like the thumping of my heart. Grass rustles behind me, and I gasp,
spinning on my heel. But there’s nothing there. I turn back to the barn and press my palm
against the wood. The door squeaks open on old hinges, and a chicken runs out, its claws
scratching across stone. I place a hand over my heart, trying to calm it.
“Theo?” I call.
Moaning comes from the back of the barn. I step quickly, following the sound,
kicking straw in my haste. The scent of dusty hay and chicken shit wafts through the open
stalls. I poke my head into each one, frantically searching for my boy.
“Theo?”
When I step into the third stall, I find him—one more body lying face down in the
dirt.
“Theo,” I say again, my voice thick.
Another thin moan tumbles from his throat. I reach down, grab his hair, and wrench
up his head.
“Ow! Mum, what are you doing that for?”

“Get up!” I snap at my fifteen-year-old son. “Now!”
Spitting out straw, he climbs unsteadily to his feet. His bloodshot eyes meet mine.
I open my mouth to speak but can’t find the words, so I shake my head instead.
“Sorry,” he mumbles.
The word pulls me out of my stupor. “Sorry?”
“I swear I was going to come home, but things got out of hand—” Vomit gushes from
his mouth, and he doubles over.
Despite all the anger and worry coursing through me, I place a comforting hand on his
back.
At three this morning, I woke up with a start and a sense of dread creeping over me. It
took all of ten seconds to understand in my bones that Theo was not home. I checked my
phone and found a text at midday telling me he was hanging with friends and would be home
later. But the exhaustion of lesson prep had scuppered my plans to wait up for him, and I’d
fallen asleep on the sofa after binge-watching some baking show.
Once he’s done throwing up, I grab him by the elbow. “Come on.” Then I march him
out of the stables. “You’ve got school in an hour.”
“Morning, miss!” someone calls brightly.
I glance down at the grass to find a hand waving at me. Empty beer bottles surround a
horizontal six-foot boy in a grey hoodie.
“Freddie Broughton,” I say. “You didn’t get into uni, then?”
“Nah.” He slumps back down.
“Miss Foster!” Another arm waves at me, this one belonging to a copper-haired boy
who failed psychology last year. “All right, miss?”
I ignore him and carry on towards the car. Theo hangs his head as other students and
former students of Hanlocke School recognise me. I nod and say hello as we make our way

through the remnants of last night’s rave. Semiconscious bodies move lazily through the
grass. Arms stretch, and hands clutch heads.
“Get in.” I open the car door, shove my son into the passenger seat, and release some
of that pent-up anger by slamming the door.
I’m barely here. Half of me is living in those hours between three a.m. and seven a.m.
when I called Theo’s phone, his friends’ phones, his friends parents’ phones, and every local
hospital. I’m still in that panic, tossing my coat over my pyjamas, running to the car in the
dark, and driving around until I heard the thumping bass.
Just before dawn broke, I finally saw the lights on the horizon that had been so
effective in drawing every wayward teenager to it like a beacon, a promise of electronic
dance music, beer, and probably drugs too. It lured my son and his mates. I knew then what
had happened and hurried to Beckford Farm to find him, my heart twisted with fear. Nothing
good ever happens at Beckford Farm. The place gives me the heebie-jeebies.
I sigh and reverse out of the drive, nodding to a second parent standing with his hands
on his hips near a doubled-over teenage girl.
“The last time I was here, I had to pick up your dad. Do you know why?”
Theo shakes his head.
“Because he almost overdosed. That’s why. This place is dangerous, Theo. You know
that!”
“I wasn’t doing drugs!” he snaps.
“Where did I go wrong? What did I do to deserve this?”
“Jesus,” he mutters. “It was an accident.”
“You tripped and fell into a rave? Beer magically flew through the air from the bottle
to your mouth? Is that what happened?”
“No.”

“You’re underage,” I remind him. “You have GCSEs this year. What are you doing?”
My fingers tighten around the steering wheel, and I ease off on the accelerator once I
realise I’m over the speed limit.
“I said I’m sorry.” He runs a hand through his mop of curly hair. A few short strands
of straw tumble out.
“Sorry isn’t good enough.”
“Stop! Stop! I’m going to be sick.”
The brakes screech. The door opens, and he stumbles out onto the verge. I roll my
eyes, thinking, What a way to start the new school term.

*

An hour later, I drive my ashen-faced son to school, taking a small amount of pleasure in how
utterly wretched he looks from the hangover. Now that all the panic and fear has
evaporated—he’s fine, after all—I grab on to the optimistic hope that this might be a learning
moment. Actions have consequences. Drink beer and pass out in a barn at a rave on a school
night, and suffer the consequences during double maths.
“See you later,” I tell him as he unclips his seatbelt. “I’ll drive you home.”
“Fine,” he mumbles.
“You’re not going out for the rest of the month, by the way.”
He says nothing, but he doesn’t slam the door. Maybe that’s progress.
I grab my bag and head into the school building, rushing up the stairs to the staff
room. I’m convinced that Ryan, the deputy head, makes a note of what time we arrive. I
won’t be winning any points for dedication on that front, but I am also a single mother, and
while I strive to be better, it doesn’t always happen.

“Lucy, I’m so glad I caught you.”
My heart sinks. Ryan, standing by the kettle with his glasses halfway down his nose,
smiles to reveal yellow teeth. He takes a step towards me so that I can smell the coffee on his
breath.
“Ah,” he says. “Did the rave keep you up half the night too? You could hear it all the
way down to Greenwood Park. Scrotes.” He shakes his head. “Where were the police? That’s
what I want to know. Anyway.” He pulls in a deep breath. “I have Miriam’s retirement
present. She left before we could give it to her.” He gestures for me to follow him over to the
sofas then shows me the bag with the gift-wrapped box inside. “It’s a clock. We didn’t know
what to get her. To be honest, you were the only one who really knew her.”
“Do you want me to pop it over?” I ask, trying to hurry up this interaction.
“That would be wonderful.” He checks his watch. “Whoops! I’d best get a move on. I
have your Theo for maths this morning.”
I stare down at the bag. Miriam and I were the only two psychology teachers in the
school before she retired two weeks before the end of last term. She hired me fresh out of
training and mentored me into the teacher I am today, which is why it was so strange to see
her abruptly leave the school without saying goodbye.
I was planning a retirement party for her when Ryan told me she wasn’t coming back.
She even left me in the lurch for the final lessons. I called her a couple of times because it
seemed so out of the blue, but every conversation we had ended quickly. She alluded to some
ill health prompting her finish early. I’d suggested a visit, but we didn’t make firm plans.
Then I lost myself in the summer and failed to follow up.
A pang of guilt runs through me. Is a clock a good retirement present? I should have
arranged a more personal gift, but with Theo going off the rails over the last six months, I
didn’t have the energy for one more task.

I quickly make a cup of tea then try not to spill it on the way to the classroom,
dodging loud, rambunctious teenagers who haven’t been together in a mob for six weeks. I’m
late to the classroom, where my students are waiting for me, sitting in clumps, their bags
strewn all over the desks and the floor.
“Sit down and shut up,” I say loudly. “Are you a psychopath?” I point at a mousy-
haired girl in the front row.
She blushes and glances away. Someone at the back giggles.
I address the room. “Welcome to psychology. Let’s find out how crazy you lot are.”

Chapter Two

“You survived!” I clap Theo on the back as he gets in the car. “Well done, lad.”
“I puked in a bin,” he admits. “Miss Patel gave me detention at lunchtime for falling
asleep in Chemistry.”
“Sucks to be you.” I pull out of the car park onto a road chock-a-block with SUVs.
“We’re calling off at Miriam’s on the way home.”
“For God’s sake, Mum—”
“What?”
He leans against the glass, and I can tell he wants the ground to swallow him whole.
There’s more colour in his cheeks compared to this morning, but he’s still suffering.
“She might have ibuprofen,” I say, feeling a tiny bit bad for him.
“Cool,” he mutters.
“When we get home, we’re talking about this,” I add. “We have to talk about what
happened because it was so fucking out of order.”
The swear word gets his attention. He sits up straighter. Good, I think.
“There is a path before you right now. Several of them, actually. I don’t like the one
you’re following. It might feel like fun, and it might feel like living, but it has a dead end
unless you take a turn onto a better, less bumpy road. You know, one they’ve actually
tarmacked?”
“Did you get that out of a book?”
“No. I made it up. On the spot. I’m smart like that. I teach A-Level psychology, in
fact.” I wink at him, trying to lighten the mood.
It doesn’t work, and we stew in a sour atmosphere until I pull onto Rosethorn Lane,
the quiet road where Miriam lives. All roads are quiet in Hanlocke. It’s one of the reasons

why teenagers congregate in the fields for raves. There’s nothing else to do. I should know. I
grew up here, too, and I was pregnant with Theo shortly after my eighteenth birthday.
We didn’t have raves. We had house parties of thirty or more kids crammed into some
parent’s little cottage, weed smoke in the air, empty beer cans spilling out of the bins, Placebo
or Radiohead CDs in rotation, unless someone got out an acoustic guitar.
How do I stop my son repeating the same mistakes I made?
“Can I stay in the car?” he asks.
“No.”
He sighs heavily. Any younger, and he’d be moaning about how unfair I am. But that
hasn’t happened since I said no to overpriced Lego sets and fidget spinners.
I grab the present. Theo hangs back, his hands shoved into his pockets. I peer up at the
stone cottage with ivy creeping up to the roof. The curtains are open, revealing the circular
dining table in the window, a vase filled with purple dahlias. I make a mental note to ask
Miriam if she grew them herself.
I have to knock three times before the door opens. The whole time we wait, I sense
Theo’s impatience. But finally, she appears around the door, all five feet of her, make-up free
for a change, and with her hair scraped back into a bun.
“Lucy, hi,” she says. “What are you doing here?”
I force Theo closer to the door and wrap my arm around his shoulders. “We came for
a chat. If you’re free.” Then I hold the bag aloft. “And I come bearing gifts.”
“Oh.” She tugs at a yellow shawl around her shoulders. “It isn’t a great time.”
I hesitate. Miriam is not generally an antsy person. I’ve never seen her raise her voice
at the kids. She always somehow managed to keep a calm exterior no matter what chaos
ensued behind the classroom door. But right now, the way she speaks quickly, almost
breathlessly, and keeps fidgeting with her clothing, makes me think something is wrong.

“We won’t stay long,” I insist. “It’s been ages since we had a good chat. I could make
us a cup of tea if you like.”
Her eyes drop to the floor before she answers. Then she takes a step back. When her
eyes meet mine again, she smiles warmly, and some of her usual character shines through.
“Goodness, Theo, you’ve grown. You must be almost six feet by now. Come through
to the kitchen. I’ll put the kettle on. I’ve got some of those biscuits you like.”
“Wagon Wheels?” he asks, his voice brightening.
She pats him on the arm. “The one and the same.”
My nose prickles with unexpected tears. One even escapes from my eye before we
reach the kitchen, though I brush it away quickly before anyone notices. But for a moment,
Theo is ten, and we’re in Miriam’s house as she makes us cups of tea and goes through the
curriculum with me. I’d just started out at Hanlocke, and I had no idea what to expect or how
to handle any of it. Mum usually babysat for me back then, but she was busy, so I brought
Theo along, feeling unprofessional. As soon as I walked into this house, I felt at home.
Miriam doted on Theo. I commented on her perfectly clean and tidy house with gingham
curtains and kitten ornaments.
Miriam’s husband, Eric, had been alive then. A mechanic, he was always tinkering
with vehicles in the driveway and was never allowed in the house until he’d removed his
boots and overalls and washed his hands. The two of them provided comfort when I needed
it, almost like a second set of parents, ones without expectations and disappointments.
“You both look very pale,” Miriam says. “You’re not coming down with anything, I
hope?”
“Theo, would you like to explain?” I fold my arms, glaring at my son.
He shakes his head sheepishly.
I turn to Miriam. “He has a hangover.”

“No. You haven’t, have you? At your age?”
“Mum, did you have to say?” he asks, his cheeks flushed.
It’s good that he feels embarrassed. He understands that he messed up and doesn’t
want Miriam, someone he loves, to know it.
“There was a rave up on Beckford Farm,” I explain. “Theo got mixed up in it.”
“Oh no. Oh, Theo, you don’t want to hang around with that lot.” She shakes her head.
“There’s some wrong’uns up there.”
I flash Theo a look to say, “See?” then take the cup of tea Miriam offers.
“Can I have some water?” Theo asks.
“Of course you can, love.”
As Miriam moves around the kitchen, I watch her closely. When she left school early,
I wondered if she had been diagnosed with a terrible illness—cancer or some other incurable
disease. She was so cagey on the phone, so closed off, that I’d backed off. I search for signs
of illness, such as a wan complexion or stiff movements, but she’s agile and ruddy cheeked.
“Shall we go into the living room?” she suggests.
As we move away, Miriam glances back at the door that I assume leads to some sort
of storage cupboard. For just a moment, her expression darkens. It’s barely perceptible, but
her entire face tightens with fear.
No. I’m seeing things. Why would Miriam be afraid?
I give Miriam the present, and she gushes over the clock. It is attractive now that I see
it close up. The brass carriage clock is similar to one my grandmother owned. A bottle of
wine and some chocolates are also included.
“We all miss you at school,” I tell her. “It’s not the same.”
“Are they hiring a replacement?”

I launch into my usual rant about budgets and how my class size has doubled because
they won’t hire another psychology teacher. Then we talk about teaching in colleges and
universities compared to school.
Theo places his head in his hands.
“Are you all right, sweetheart?” Miriam asks.
I stroke his shoulders. “Do we need to get you home?”
“No, I’m fine. Stop fussing. I just have a headache.”
“Crap.” I slap my forehead. “I meant to ask you for some ibuprofen—”
“I’ve got some upstairs.” She stands, pushing back her chair. Then she hesitates. She
looks at the kitchen for a moment then back at us. “Stay right here. I won’t be a sec.”
After Miriam leaves the room, Theo pushes his empty glass towards me, asking for a
refill. I head into the kitchen, fill the glass, and pause, wondering why Miriam seemed afraid
when she looked at this door. It’s probably nothing. Maybe she saw a spider crawl underneath
and is concerned it might come out.
No. Miriam isn’t afraid of spiders. I’ve asked her to remove them from the classroom
on occasion.
Leaving the water on the counter, I make my way over to the door and stand in front
of it. I try the handle, but it’s locked.
This is silly. I’m basically snooping. I turn around, heading back to the glass of water
standing on the kitchen counter.
Then a baby begins to cry.
Every hair on the back of my neck rises. Goose bumps spread down my body, to my
fingers and toes. There are no neighbours here, and the baby cry did not come from outside
the house. It came from behind that door.

Chapter Three

I’m frozen for one, maybe two seconds in total, unable to even take a breath.
“Mum, where’s my—?”
“Shush!”
Theo’s chair creaks as he gets up and walks into the room. I press my ear to the door,
my heart pounding. Did I just hear what I thought I heard? The baby wails.
I try the handle again. Then I throw my weight against the door.
“Mum, what are you doing?”
“Go and get Miriam.” I wave an arm at him. “We need to open this door. Now.”
I take a step back and think. How is this possible? I don’t understand what’s going on.
Could a child have somehow snuck into Miriam’s cellar and ended up trapped?
I press myself against the door again. “Hello? Is someone down there? Are you
okay?”
“Someone help!”
The sound of another voice jolts through my body. Who is that? A woman, I think but
maybe a child.
“Are you okay? Are you trapped?” I call.
Before I can answer, my head whips to the right. Footsteps tap down the stairs. “Lucy,
stop! Stop what you’re doing! You don’t understand!”
“There’s a child down there! I heard a baby cry. Maybe a toddler crawled in through
an open window or something. Does your cellar have a window? Do you have a key? We
need to open the door now.” I turn to Miriam, who is almost at the kitchen, shuffling quickly.

“No. You can’t. You can’t do that. Stop!” A box of ibuprofen drops to the floor as
Miriam rushes towards me. To my horror, she raises a fist, intent on hitting me. But Theo
grabs her by the waist and pulls her back.
I point at the door. “There’s a… a child or a baby down there.” The words come out
high and more like a question than a fact. I sound like someone in a state of shock. “Miriam.
Why did you try to hit me? What’s going on? Where does this door lead?”
Miriam’s eyes turn dark. “You don’t know what you’re doing.”
“Please give me the key to the door.”
She’s silent, staring at me with eyes that have lost their usual lustre. They seem
hollow now, like her personality has been scooped from her being and thrown away. The
blood drains from my face, and a wave of light-headedness washes over me. This situation
isn’t right. She’s not reacting like my friend would usually react in this situation, and it’s clear
she’s not going to give me that key.
I pull in a deep breath before grabbing my phone from my trouser pocket to dial the
emergency services.
“Stupid girl,” Miriam mutters. Then her voice cracks. “It’s all over now. Everything
I… It’s gone.”
After reeling off the address to the 999 operator, I stare at my friend—my
mentor—bewildered. “Did you put the child in your cellar?”
She won’t look at me.
“I don’t understand.” My voice cracks again.
Nothing makes sense. Miriam isn’t the kind of sadistic person to trap a child or a baby
in her cellar. She took me under her wing and gave me pointers when I needed them at
school. She buys my son’s favourite biscuits just for him. Miriam gave special attention to the
kids at school who needed it and brought in fruit for anyone who hadn’t had breakfast.

Yet the cold, hard details I relay to the operator over the phone tell a different story.
“A baby crying in the cellar… behind a locked door… and a voice too. No, I don’t
know who. Come quickly.”
I turn to Miriam. “Where is the key?”
She looks away. I take a step forward.
“Miriam, please.”
But she won’t even look at me.
I open kitchen drawers, rummaging through tea towels and cutlery. “Theo, let her sit
on a chair, but don’t let her leave.”
He leads her by the elbow to the kitchen table. It’s like she’s shut down. Her
expression is blank, her eyes unfocussed. Why does she have a baby in the cellar? Who in
their right mind…?
I move to the dresser, yanking out the drawers underneath the shelves. Then I tip them
out onto the tiles, moving the items around with my hands. The key finally emerges from a
set of napkins. I grasp it, rush over to the door and try the lock. My hands are shaking. Sweat
trickles down from my temples. The key works, and the door swings open, revealing the dark
stairs travelling down into an abyss.
The baby continues to wail.
“Is someone there?” asks a voice. The same one I heard a few moments ago.
My heart tugs. I recognise the sound of a teenage girl’s voice when I hear one. Over
my years as a teacher, I have heard girls cackle with their friends, belt out whatever song is
number one, and cry about their boyfriends. But I’ve rarely heard the sound of fear in their
voices—until now.
I flick on the light switch by the door.
“Theo, can you stay up there with Miriam? Are you all right?”

“Yeah.”
He’s pale, not from the hangover this time but from pure shock. I want to hug him, but
I need to go down into that cellar and find the crying baby. I have to do this.
Facing the cellar again, I call down. “Hello? Is someone there?”
“Yes! Please help me! I can’t get her to stop crying.”
“It’s all right. I’m coming down now. I’ve called the police, and you’re going to get
help.”
“Where’s Miriam?” the girl asks.
“She’s up here.” I lick my lips then add, “She isn’t going to hurt you.”
The words feel like rocks in my mouth. The thought of Miriam hurting anyone is
beyond strange to me. Ten minutes ago, I would have called it impossible.
I make my way down the stairs, moving quickly in socked feet. Wooden steps lead to
an open space covered in dust and cobwebs. A few crates of wine lean against one wall and
some boxes marked “Christmas decorations” sit by the other. At the back of the space is what
appears to be a room built into the cellar. A padlocked blue door faces me. The room has
breeze-block walls and no windows.
“Are you there?” comes the voice from behind the blue door.
“I’m here. I need to find another key. Or bolt cutters.” I run a hand through my hair.
The baby continues to cry, screaming out dank air. “What’s your name?”
“Alice,” she says. “My baby is called Jess.”
“Okay, Alice. I’m Lucy, and I’m going to get you out of here.” Before I leave, I ask,
“Why did Miriam lock you in here? I don’t understand.”
A sob comes behind the wooden door. “She said she was going to cook me a hot
meal. Sh-She said she was going to…” Her voice rises in pitch. “Help me. But then she put
me in here.”

“How long have you been in there?” I ask.
After a moment of silence, she replies, “I gave birth in here.”
I suck in air. No. It’s too horrible to contemplate. This doesn’t happen here in
Hanlocke. Teenage girls don’t give birth in cellars. What’s happening?
“Mum? Is everything okay?”
“I’m fine, Theo. Is Miriam still sitting down?”
“Yeah.”
I place a palm on the door, and peeling paint crumbles under my fingertips. “Alice,
I’m going to find the key and come back. I won’t be long. Okay? It’ll either be me or the
police, but you’re going to be safe soon. I promise.”
“Hurry,” she says. “I hate it down here.”
I stay true to my word, rushing up the stairs so quickly that I trip over the last step,
barrelling back into the kitchen.
“Where’s the key, Miriam?” I demand. “Where is it?”
Theo swallows loudly. He paces back and forth. But Miriam is stock-still, her
expression unreadable.
I stride over to her and rip the shawl from her shoulders. She doesn’t even flinch.
Then I reach into her pockets and find a small piece of metal.
I suspected she had it on her. Otherwise, it would have been with the other key.
After rushing back down to the cellar, I fiddle with the padlock, swearing when I drop
the tiny key onto the stone floor. My heart pounds so hard that it pulses in my ears and teeth.
Then the chain falls, clattering hard. I pull heavy bolts across until the door swings open. ...