It’s a normal day in Hong Kong when suddenly
the biggest tsunami in history hits the city, quickly flooding the streets and filling up the
buildings. People run away in panic trying to find a safe spot where to hide, but the water is
faster than them. Only those who manage to get to a floor high enough survive, and Hong Kong loses
most of its population in just a couple of hours. Five years later, Asha still has nightmares of the
horror she felt that day. However every morning she bottles up her fear and pushes through to keep
on surviving. She’s living in a high building that is in ruins, and she takes advantage of the trash
to keep her things hidden from potential enemies. She’s been savaging anything useful for the water
for years and has created hiding spots all over the apartment, like making a hole under the couch
cushions. Every morning, she goes to the roof and gets some clean water from her secret stash, which
is also carefully hidden. After drinking some tea, she listens to the radio, but she ignores the
recorded message informing about a government shelter with supplies and chooses music instead.
She’s careful to use headphones to avoid making extra noise. Next she uses a towel to gather the
morning dew, which she adds to her stash of water bottles. She also measures all the bottles to
keep track of how much clean water she has left, and she can’t help worrying because it hasn’t
rained in a while. Once her chores are done, she eats instant noodles while remembering the
beautiful restaurants with delicious food she used to visit with her friends. Afterward Asha
uses binoculars to watch over the area. Only the top of the buildings can be seen sticking out of
the water, and occasionally those buildings would start crumbling down. She also makes sure that
the few surviving neighbors are still in their apartments. Suddenly she sees a box floating
in the water and rushes to a different window, where she’s installed a makeshift harpoon-like
mechanism that she uses to scavenge. With one quick shot she manages to catch the box, but when
she tries to pull it in, something in the water drags the box down and makes her hit the edge
of the window, hurting her arm. Asha ignores the pain and keeps on pulling against the mysterious
strength, falling back from the whiplash when the creature finally lets go of it. Then Asha brings
the box inside, and the animal has its revenge by sending a wave against her. The box mostly
has trash in it, but she also finds a bottle of alcohol. On her way back to the roof, Asha stares
at the door at the end of the corridor before moving again, clearly upset. On the roof, she uses
the alcohol to clean her wound before wrapping it up and drinking the pain down. In the evening, she
hears screaming and looks outside to discover two boats of violent scavengers have come by and are
attacking the neighbors. There’s also a man on the other roof looking at her building, so Asha hides
for a few seconds before looking again. It seems the boats are coming to her place, so she rushes
downstairs, hides all her daily things, covers her mattress, and even throws some dirt on the hallway
to make it look live-in. Then she hides behind a fake wall in a closet, making sure to keep silent
as the scavengers get into the room and begin looking around for food, even checking the closet.
Thankfully they don’t find anything, but Asha gets startled when she hears a shot - a boy just shot
his gun because he thought something moving, but it was a mistake. After the group is gone, Asha
cries in relief and tries to calm herself down with a nice memory. Before the tragedy happened,
Asha had gained a half-sister and she took her out for a meal to start bonding. The next day, she
finds another box and among all the junk inside, she’s excited to find a jar of honey. However
her happy moment is ruined when she sees a body floating in the water. Sometime later while Asha
is busy, someone sneaks inside and starts taking things from Asha’s secret spots. Asha thinks she
hears something but can’t see anything, so she ignores it for now. When she gets ready for bed,
she hears another noise and goes to investigate with her flashlight, but once again there’s
nothing. Next she washes her face and leaves the soap out on purpose to finally catch the intruder,
who turns out to be a little girl. Asha grabs the shoulder to confront her, but the child kicks
her and runs away. She takes a few more things including Asha’s makeshift lamp and goes down the
corridor, but before she can open the mysterious door, she hears Asha coming and leaves again. That
night, Asha dreams of the time she went shopping for clothes for her sister’s birthday, and how
she told her best friend that she was eager to leave her parents’ house. When she wakes up, she
notices part of her food stash is missing, so Asha begins following the empty wrappers on the floor
and finds the girl sleeping with the lantern. She doesn’t have the heart to wake her up, so she
goes to do some cooking instead. When the girl finally awakens, she goes around looking for
more hidden compartments. Inside a fake outlet, she finds an envelope with pictures of Asha
and her sister, only to be caught red-handed. The child runs away and Asha hurries to put the
pictures back in their place, not noticing she accidentally dropped one. Afterward she makes a
second portion of noodles and brings it to the child while remembering the night of her sister’s
birthday dinner. Their parents gifted her the family’s necklace, which made Asha angry because
as the first child, she was supposed to get it. An argument ensued and Asha ended up leaving. Back to
the present, it’s shown that Asha is wearing that necklace now. The girl ignores the food offer, so
Asha leaves it next to her and leaves. The child eats it all and moments later, she notices Asha
left a mattress for her too. She doesn’t use it, but the next morning, she gives Asha back all
the things she stole. For lunch, Asha makes two portions of noodles again and leaves one for
the girl to then go eat on the roof. However the child soon joins her and copies everything she
does, causing them to laugh and bond. It makes Asha remember the happiness of her old life again.
In the evening, the girl finally accepts to take the other mattress and sleeps next to Asha. Soon
she starts crying and tries to hide it, but Asha tells her it’s ok to cry and be scared. The girl
misses her family but thinks she’ll see her mom soon because she’s building a boat to find it. She
also mentions her name is Hei Hei. After another night full of nightmares, Asha takes Hei Hei with
her to the roof to go through the routine. Hei Hei is playing around with the door and removes
the tape Asha put on the lock, so when the door accidentally closes, they can’t open it from the
outside. Asha is upset, but Hei Hei immediately shows her she can pick locks and opens it again.
Later while Asha is getting a new meal ready, she realizes her necklace is missing. At that
moment she hears some noises and looks out the window to discover the scavengers are back, so she
asks Hei Hei to stay silent while they wait until they’re gone. Later while Asha helps Hei Hei get
clean, the girl asks her to leave together, but Asha refuses. She says this is her home and that
there’s nothing out there anyway. Then Asha asks Hei Hei if she took her necklace, but Hei Hei says
she didn’t and runs to another apartment, offended by the accusation. In the evening, Asha has dinner
alone and notices there’s water missing, so she goes to investigate and discovers Hei Hei took
it to wash. This triggers another memory of her hearing news of a typhoon coming to neighboring
countries, and how she fought with her mother, who wanted her to get married and be a good wife.
That night the nightmares get worse and Asha keeps seeing all the bodies in the water. When she
wakes up, for a second she mistakes Hei Hei for her sister. Afterward, Asha teaches Hei Hei
how to deal with the electricity in the building, but Hei Hei interrupts to ask about the door at
the end of the corridor. Asha asks her to ignore it because that room stinks and if they open it,
the smell will spread everywhere. Another memory shows Asha watching the news, which was reporting
the complete destruction of Singapore by the floods. Her mother turned off the TV and told her
about the next family meeting, but Asha couldn’t go. Another argument ensued and Asha told her
family they made her feel like a prisoner before leaving the apartment. Back to the present, Hei
Hei is using the radio and hears the message about the shelter, so she rushes to Asha to ask to go
there. Asha refuses, explaining it’s dangerous to go out. An argument ensues, so Hei Hei calls Asha
angry and bitter and leaves the room. Following her into the other room, Asha discovers Hei Hei is
building a raft with trash, she’s also got a flare gun. Asha immediately takes it from her and makes
a confession: some time ago, she tried to leave, and the situation out there was so horrible
that she had to come back. After they reconcile, Asha remembers how her sister followed her out of
the apartment after the fight with her parents, asking her not to go. Asha explained it was
time for her to move out, but she promised they would still hang out. The next morning it’s
finally raining, so Asha and Hei Hei rush to the roof to gather lots of water and put it away
properly. While they’re working, Hei Hei notices that Asha’s necklace had simply fallen. Then Asha
discovers the photo that got left behind and she’s overwhelmed with memories, so Hei Hei comforts her
and reminds her they have each other. When Asha goes to bed, she’s surprised to find something
under her pillow: it’s her necklace, which fell because the clasp is broken. Feeling bad about
how she treated Hei Hei, the next morning Asha begins working non-stop until she manages to
build a raft. Hei Hei gets super excited, and Asha remembers the night of the argument again.
Her sister was trying to tell her she left the necklace in Asha’s jacket when suddenly people in
the street started to run in panic because there was a huge tsunami behind them that hit the
streets in seconds. Back in the present, Asha decides to gift Hei Hei her necklace. Sometime
later, the duo gathers supplies to get the raft ready to leave. Hei Hei is listening to the
radio and the headphones accidentally disconnect, causing the music to loudly echo in the room.
Asha rushes to turn it off but soon they hear the voices of the scavengers outside. Panicking,
the duo rushes to hide all their personal objects as fast as possible, then Asha pushes Hei Hei
into the hole behind the fake closet wall. There isn’t enough room for both of them there,
so Asha will be hiding in the stinky room. Soon the scavengers enter through the window, but Asha
hides just in time in the stinky room, where she finds her old family pictures because this is her
old apartment. The scavengers start a much more violent search this time, destroying anything they
could find including the raft. A guy comes to the stinky room and gags at the putrid smell, but he
keeps moving and removes some old sheets only to find the bodies of Asha’s parents, causing him to
puke. At the same time Asha throws out too while remembering the night of the tragedy. The wave
was taking down everything in its path, killing dozens of people per second. Everyone started
to push each other for a chance to survive, so Asha dragged her sister into a building to take
the stairs, but soon the crowd was following them. Back in the present, the scavengers are taking all
the food and staring at Asha’s pictures. The boy finds the closet and notices something weird,
so the other scavengers help him move the fake wall and they capture Hei Hei. Asha hears all this
from her hiding spot in the stinky room and once again has a flashback: when they were going up
the stairs, the sister tripped and fell behind, so she was trampled by the crowd. Asha was
panicking and kept on running, not noticing her sister was missing until she made it to the
roof. Suddenly Asha hears a scared Hei Hei tell the group where she is and the scavengers quickly
find her, knocking her out. When she wakes up, Asha is tied up and the foreign scavenger tries
to take advantage of her, but at that moment the leader calls him over. Moments later, Hei Hei
and all the supplies are taken to the scavengers’ boat. Asha is soon dragged out too and looking
at Hei Hei reminds her of her sister, making her realize she can’t make the same mistake again.
She pulls at the rope, but the guy pulls back and makes her fall into the water. Luckily there’s
a broken CD nearby, so Asha uses it to attack the man, which causes him to angrily try to drown
her. After some struggle, Asha finally reaches the flare gun in her pocket and shoots the guy,
killing him. The other scavengers hear all the noise and come back into the building, but they
don’t see Asha. As the group splits to search, a big guy hears Asha cry and comes after her,
but this is part of her trap: she makes him fall with some rope, then uses a guitar to beat
him to death. Next, she takes his knife and runs into another room to turn on the radio. Soon a
scavenger follows the noise and Asha jumps on him from behind, stabbing him with the knife. It’s not
enough and the guy starts fighting Asha, throwing her on a mattress to try to choke her. Thankfully
she manages to reach the knife and starts stabbing him repeatedly until he’s dead. Then the female
scavenger also hears a noise and finds a can with fire inside. Asha surprises her by throwing oil on
her and pushing her into another room, where she sets her on fire before blocking the door to let
her burn slowly. The leader hears her screaming and moves in that direction, but when he takes
the stairs, Asha jumps on him to stab him. Another fight ensues during which the leader hits Asha a
couple of times before trying to choke her. Asha continues to struggle and reaches up to grab the
light tube, causing darkness to take over as she beats the guy to death with it. When she turns on
her flashlight, the boy shows up and opens fire, so Asha immediately runs to the roof. The boy
goes after her and as soon as he steps outside, Asha closes the door after having removed the
tape, trapping the scavenger on the roof. The boy starts begging for help with an innocent
voice and Asha considers taking pity on him, but soon he starts shooting at the door so
Asha leaves. There’s only one scavenger left on the boat, watching over Hei Hei. Asha goes
to the window and uses her harpoon-like device, but she misses the shot and it falls in the water.
When the guy moves to check on the noise, Hei Hei uses the chance to push him off the boat, but the
man grabs her and makes her fall too. A desperate Asha jumps into the water to save her while the
man resurfaces nearby, only to be eaten by the sea creature. After a few seconds of silence, the
duo resurfaces too, all safe and sound. They swim to the boat and finally get going, knowing that
all the supplies the scavengers stole will keep them going until they find the shelter. That
night, Asha finally sleeps without nightmares.
