In this post-apocalyptic world, a toxin known as the Shred has spread around the world and
causing people to lose their memory.
A wanderer's trying to find cover in the woods when he comes across a huge glasshouse with
a "no trespassing" sign, but he comes closer anyway and ends up being shot by Bee.
It turns out that in this house lives an isolated family, consisting of Mother and her children
Bee, Evie, Daisy, and Gabe.
Mother has designed a whole system to guarantee their survival, which includes growing their
own vegetables for food and clean air, and making everyone wear necklaces with their
initials to help with their memories.
They also have masks to protect themselves whenever they go outside, although Gabe once
forgot to wear his when he was a little boy and now he suffers from a dementia-like condition
that requires him to be shackled to bed if he's having a bad day.
People from outside aren't allowed into the house.
Any stranger that dares step on their property is immediately shot after they check it isn't
their lost sibling Luca, who should know a code to identify himself if he ever returns.
When a stranger's killed, the girls take certain parts of the bodies for rituals and fertilizer,
and then they bury the rest outside.
The man that Bee shot today has a photograph in one of his pockets, so Evie takes it for
herself before they get rid of him.
Later, she hides the photograph in a special box that she keeps buried in the greenhouse.
When it's time for the ritual, the family gathers around the body parts and expresses
their gratitude for having the protection of the glasshouse.
This is why they've painted all the glass walls with drawings that represent the story
of Mother settling down here with her family, it's part of their promise not to forget.
One evening, Bee's outside on sentry duty when she suddenly sees a Stranger approach
the house after taking off his mask.
Bee uses a flashlight to do the code and the Stranger doesn't answer so she should kill
him, but for some reason, seeing his face makes something flash in Bee's eyes.
When the Stranger passes out, Bee decides to break the rules and bring the Stranger
inside.
Mother's obviously furious and wants to get rid of him, but Daisy points out that the
second rule says everything in the sanctuary is sacred, so now the Stranger is under their
protection.
Mother decides to at least use the occasion to teach the girls how to stitch a wound using
the Stranger's hurt leg.
The next morning, the Stranger wakes up shackled to a bed and finds Bee sleeping next to him
on the floor.
Gabe wakes up shackled as well and discovers he's wet the bed, so Evie goes looking for
Bee to help her clean up.
Bee's desperate to be with the Stranger, so she helps Evie quickly take off the sheets
without caring that Gabe's still on the bed and then leaves her to clean Gabe himself
alone, which is a rather awkward moment between siblings.
Then Bee rushes back to the Stranger to take care of his beard, only to discover he's already
awake.
Bee's scared but still tries to ask some questions that the Stranger won't answer.
After Bee and Evie change his bandages, Mother comes over to interrogate the man, who says
he thinks he never had a name.
He explains there's almost nothing left of civilization and the few wanderers left scavenge
or starve.
One of them attacked the Stranger and gave him the wound.
He wonders if he's allowed to leave now, but Mother won't let him because he knows about
them, so he must stay and work like everyone else.
Later, Evie realizes Gabe is uncomfortable around the Stranger, so she tries to cheer
him up by showing him the toys he used to make, but he can't remember them.
Bee is more extreme and brings Gabe closer to the Stranger to make him touch his face
and prove they're all the same, but Gabe's still wary.
The next morning, the Stranger is sent to work in the greenhouse, although he's still
shackled for security.
Bee continues to be obsessed with him, so she brings him a plate of fresh fruit and
is delighted to see him pick a strawberry, she also promises to teach him how to read.
Whenever Evie needs help with chores, Bee tries to get her to do it alone so she can
spend more time with the Stranger.
This frustrates Evie and causes her to remind Bee she can't trust a random man, but Bee
ignores her because her crush is already too strong.
When it's time to reseal the windows, Bee works while explaining to the Stranger that
the images represent their story.
The Stranger notices the drawing of a man and asks about him, to which Bee responds
he was "her everything".
During dinner, Bee tries to get the Stranger to sit at the table, but Mother forbids him
from taking Luca's place and sends him to seat with the plants.
When the Stranger asks who Luca is, he learns he was their sibling, who left to look for
survivors and hasn't come back.
Days pass and the Stranger's leg slowly gets better.
Daisy asks him about animals because she never saw one, so the Stranger draws a horse and
promises to carve one for her if she can't get him a knife.
Thus Daisy steals a knife from her sister's basket to bring to him.
Seeing Daisy playing with the Stranger makes Gabe jealous.
Sometime later, the Stranger finishes carving the horse for Daisy in the form of a puzzle
to put together.
Gabe finds it and the Stranger allows him to play with it, but Gabe can't solve it.
Feeling like he's being replaced, Gabe begins throwing a rather violent tantrum and tossing
things around, and when the girls come to check on him they can't stop him.
Since it's an emergency, the Stranger convinces Daisy to free him and he gets to tackle Gabe
to the ground to calm him down.
In the evening, Bee looks at herself in the mirror and discovers a bruise on her face
left by Gabe's tantrum.
The Stranger comes closer to tease her for it and Bee accidentally calls him Luca, prompting
the Stranger to admit he can't be Luca because he feels things for Bee that a brother shouldn't.
Shockingly Bee's delighted to hear this because Luca also felt forbidden things for her.
The family doesn't keep the Stranger shackled anymore and he's free to wander around the
house.
One morning, the Stranger finds Bee with her box and asks about it, so Bee explains it
used to be a game she played with Luca.
The Stranger wants to play but Bee turns him down because he isn't Luca, she also points
out he shouldn't be participating in all the rituals like the singing in the garden because
he's an outsider.
The Stranger disagrees because he knows those rituals are done to remember who they are,
implying he may need to remember as well.
Afterward, he goes to see Daisy and Bee to ask them about the box too.
Daisy doesn't remember it because she was too little, but Bee does because Luca always
hid strawberries in it, which are Bee's favorite thing.
Later, the Stranger goes to see Evie to apologize for offending her, yet Evie still doesn't
trust him and admits she would've shot him if she had been on sentry duty that day.
The Stranger wants to help with the sentry shifts, but Evie just tells him to watch himself.
On his way out, the Stranger bumps into Mother, who explains everything has a purpose and
she already has one in mind for him, but he won't find it with Evie.
The next day, the sisters are working on the plants when suddenly the Stranger comes by
to leave a strawberry for Bee.
In Bee's eyes, this is a sign that he really is Luca and just forgot, but Evie still thinks
it's a manipulation trick.
In the afternoon, the Stranger joins Bee during her sentry shift to take their relationship
to their step.
The Stranger offers Bee gratification, not stopping even when Bee has to shoot another
wanderer.
The new body is taken care of as usual, and once that's done, Bee and the Stranger get
frisky in the house's entryway.
Since all the walls are made of glass, they can be seen by Evie when she passes by, and
this triggers an old memory: she had seen Bee do the same thing with Luca years ago.
This distraction caused her to ignore little Gabe when he asked to go out.
Suddenly, the Stranger raises his head and sees Evie, so she runs away.
Later, the Stranger finds Evie and wonders if she likes watching, for which an offended
Evie throws her spade at him as she explains she won't be manipulated like her sister before
leaving.
At that moment, the Stranger notices something weird in the dirt and finds Evie's box, inside
of which there's a little bag with Lucas's name containing two old batteries and a necklace
with the letter L. The Stranger goes to ask Daisy about these necklaces, learning that
Mother made them when the kids were born and they aren't supposed to take them off.
When the time comes for another ritual, the Stranger joins them around the table and angers
Evie, who thinks an outsider shouldn't be ruining the sacred ways.
The Stranger responds by taking out a bag of coins he had with him when he arrived and
Luca's necklace comes out as well.
Since Evie won't admit she had hidden it, the Stranger says the necklace had always
been with him and that he simply forgot what it meant, but now he knows he truly is Lucas.
Bee and Daisy believe him, but Evie accuses him of attacking the real Lucas to steal it,
triggering an argument that Mother cuts short by congratulating Evie for protecting the
family.
Upset over the obvious favoritism, Bee reminds everyone that Gabe's condition is Evie's fault
for spying on her sister instead of stopping him from running outside unprotected, causing
Evie to leave in tears.
At dinner, the Stranger finally gets to sit at the table, and all these changes have Gabe
on the edge.
Later, Evie goes to ask Mother why she's the only one that can see the truth, but Mother
simply tells her not to worry because she has a plan.
Once a child comes, the man will be gone because Luca always leaves.
That night, the siblings have to hear Bee and the Stranger getting busy on Bee's bed.
A few days later, the Stranger's leg is finally fully healed, but Mother still doesn't let
him take sentry shifts alone.
When the girls are doing the washing, Evie notices Bee hasn't had her monthly bleeding
and lets Mother know about it.
Mother begins keeping track of Bee's monthlies with her calendar and a few weeks later she
informs her daughter that she's indeed pregnant.
Bee's very happy to hear the news, but her glee turns sour when Mother explains their
resources are limited, so Bee will have to choose between keeping the baby or the Stranger.
Bee begins crying and yelling to show how upset she is, and this triggers one of Gabe's
panic attacks, making him run outside.
Evie rushes after him as memories come to her of the day the same happened when he was
a kid and he lost his memory, bringing all the guilt out.
Suddenly the Stranger shows up without a mask and picks Gabe up to bring him back inside
before telling Evie that this isn't her fault.
Evie still cries while she explains Gabe had a beautiful mind that he lost because of her,
but before the Stranger can comfort her, a jealous Bee interrupts them and reminds the
Stranger he must come with her for the next sentry shift.
When they make it outside, Bee tells the Stranger she's pregnant and that he'll need to leave,
but he refuses to do so, hugging Bee and promising they'll make Mother see reason.
Meanwhile Gabe sees Evie napping and gets on her bed too to try to reach his peak.
Evie wakes up and pushes him off, but to avoid getting him more upset, she offers to help
in a different way.
Later while everyone is resting, Evie leaves the bed because she can't sleep, and the Stranger
follows her.
He tells her she doesn't need to live in guilt forever and that she shouldn't be doing those
things with Gabe if she doesn't mean it.
Evie disagrees because Gabe deserves to be happy, but the Stranger thinks so does she.
The next day, the Stranger teases Gabe for his feelings for Evie and points out she doesn't
love him, she just pities him.
This angers Gabe and makes him throw another tantrum that breaks a window.
The girls rush in to seal it before the toxin gets inside and Mother scolds Gabe for what
he did, but the Stranger says it was an accident.
Later, Mother tells the Stranger that she finds it suspicious that Gabe had been around
him both times he lost control.
The Stranger admits he thinks Gabe's getting more dangerous and perhaps he would be happier
out there with no memories, but Mother refuses to change her decision and would rather keep
Gabe than a random man.
When night falls, Mother shackles Gabe to the bed and reminds him of their story together
to make him feel loved.
On her way out, she comes across the Stranger, who understands the lady can't be manipulated
like the girls and decides to kill her right there in the greenhouse using a garden tool.
Afterward, the Stranger leaves the body and the tool beside Gabe's bed to make it look
like he did it.
When Gabe wakes up and finds his mother dead, the Stranger shows up and accuses him of murder,
which angers Gabe and makes him attack the Stranger.
The girls hear the commotion and arrive just in time to see the Stranger push Gabe away
from him, so when the man says Gabe killed Mother, Evie believes him and breaks down
in tears.
Bee's very upset but refuses to believe Gabe did it, so she tries to think of an explanation,
like maybe Gabe had a nightmare and killed Mother in his sleep without knowing.
Later, the Stranger visits a shackled Gabe to gag him up before opening the window, saying
it's for the best.
The Stranger explains he had to watch his loved ones disintegrate and wanted to forget
as well, but when he took off his mask, the toxin didn't hit him.
He doesn't know why he's immune but he does know memory equals pain, so letting the toxin
inside will help Gabe be happy again.
The girls begin preparing Mother's body for the ritual, but Daisy finds the idea of doing
those things to their own mom disturbing, so Evie takes her away to calm her down.
She doesn't realize she's left her box behind and Bee takes the chance to take a look, finding
the little bag with Luca's name and the two batteries.
This triggers a memory of her shooting a wanderer that she never told her family about, so she
runs outside and digs out a grave in the garden to find a flashlight that makes her remember
it all.
It turns out that the man Bee had killed was the real Luca, and he hadn't been able to
return to code because his flashlight's batteries were dead.
When Bee checked the body, she found the flashlight and the necklace, so after burying them all
together to hide the truth from her family, Bee took her mask off in order to forget about
what she did.
Since the batteries and the necklace were in Evie's box, it means she knew about what
happened all along.
Bee runs back inside to yell at her sister for making her think Luca could ever come
back, but Evie explains she did it to protect her from a bigger pain.
This inspires Bee to ask Evie to go outside together, but Evie refuses to lose her sense
of self and tries to stop her.
The Stranger shows up to stop their struggle and when his attention falls on Evie, Bee
gets jealous and runs outside to forget.
Evie wants to go after her, but the Stranger stops her, reminding her she has a right to
her own life.
At that moment, Daisy comes to tell the others that Gabe has changed: he's silent in bed,
as if he wasn't there anymore.
While Evie tries to figure out what's wrong, Bee comes back inside and doesn't recognize
the Stranger, confirming the toxin has made her forget.
Evie begins to realize she's slowly losing her whole family to the toxin, leaving her
to be the only one that remembers.
The Stranger reminds her that he can't forget either and promises to support her, so Evie
agrees they won't tell anyone about the bad things that happened and will work together
to protect the family.
Then, the Stranger picks up Evie to get frisky with her in Bee's bed while a catatonic Gabe
hears them.
From then on, the hierarchy changes around the house.
Evie and the Stranger are now the family leaders, and Daisy finally comes to terms with the
fact she's Bee's daughter, not Mother's.
The real Luca had impregnated Bee and then he left when Mother made her choose between
baby and boyfriend.
After the new family does the ritual for Mother's body, they begin a new happy life together,
repainting the glass pictures to represent the new members.
Bee doesn't wear a mask anymore when she goes outside, and Evie hopes that since the Stranger
is the father, the baby will survive with their dad's immunity.
Gabe may not speak, but he does start to act on his own, and one afternoon, he begins digging
in the garden because a memory has come back to him.
He finds two skeletons wearing Eevie and Bee necklaces, revealing that the living ones
aren't the originals either.
Mother has always been a believer in balance, so she would use a new wanderer as "Luca"
every time she need to replace a kid, and once the baby was born, she would put up the
excuse of the choice, meaning Luca always leaves.
Meanwhile the Stranger, now officially the latest Luca, has started to take sentry shifts
on his own.
When a young healthy wanderer trespasses into their home, Luca decides it's time for a new
replacement and shoots Gabe instead.