Inside an empty store, Carol is trying to consume any medicine or energy drink she can find in order
to try to keep her body awake while dangerous forces keep banging on a door, trying to reach
her. This mess started a few days ago. On its way back to Earth, a space shuttle suddenly explodes
and its pieces scatter across many states in the USA. Soon all media outlets are covering the news,
saying it’s a sign of alien invasion. Most people become terrified and hesitate to touch the debris,
but there are still lots of opportunists that sell what they can salvage on Ebay. Tucker, head of the
Center for Disease Control, arrives at one of the crash sites for inspection and learns that a piece
of debris is laced with a mysterious organism that has the ability to withstand enormous levels
of radiation. The organism can also multiply at a rapid rate, implying that it is from another
planet. On his way out, Tucker accidentally touches a small piece of debris and receives a
cut on his finger, but he doesn’t think much of it and leaves. Later that evening, Tucker goes home,
only to find his dog growling at him before ignoring him for no reason. When he goes to bed,
Tucker’s body starts sweating profusely and experiences an intense cellular condensation
on the face, as if something has taken over him. Meanwhile Tucker’s ex-wife Carol hears her
son Oliver screaming because of a nightmare. She immediately rushes to his room to wake him up and
stays with him to comfort him for the rest of the night. The next morning, Carol gets a call from
Tucker asking to see his son, which is not normal for him. Carol says no and hangs up. Afterward,
Carol drops Oliver at school and goes to her office, where she works as a psychiatrist. On
her way there, she runs into her best friend Ben, who offers to give her a ride. Ben is a doctor,
and he shares with Carol the fact that the government is hiding something serious from them,
as all the researchers on the crash site have resigned. Carol is in no mood for politics and
complains about Tucker instead, commenting on how he has been acting very strange lately and how he
suddenly wants to see their son after being away for four years. As soon as she makes it to her
office, Carol sees her first patient Wendy, who shares that her husband has been acting very weird
lately. A few days ago, he came to their home and the dog, who usually is a good boy, started
growling at him for no reason, and her husband just killed the poor creature without showing any
emotion. Carol immediately realizes that something is wrong, but for now, she just prescribes a new
medicine for Wendy. In the evening, Carol and her neighbor take their children out
for trick-or-treating. When they approach certain house, the family dog starts barking like crazy,
and the owner swears it’s a good pet the rest of the time. The group tries to leave, but suddenly
the dog lunges toward one of the boys and tackles him to the ground. The boy doesn’t seem bothered
though, in fact he squeezes the dog’s mouth with his bare hands until the owner comes to take the
dog away. It’s revealed the boy is wounded, but he still keeps a poker face. Afterward the group
goes to Carol’s home and while the boys share the candy, the neighbor shares that her son has
been acting very strange the last few days, almost as if he has lost his emotions. Suddenly, Oliver
starts screaming from another room, and when Carol rushes to him, she finds a strange piece of flesh
coming out of his hand that he got from the candy. The next morning, Carol sees a terrified woman
running through the streets but ignores her. She takes the strange flesh to Ben, who shares
it with his scientist friend Stephen. He promises to take a look, but the testing will take a while.
Meanwhile a mysterious virus has started to spread through the country causing lots of death every
day, but nobody knows the cause. Soon an emergency meeting is held in the capital and Tucker
explains that the new virus is spreading at an unprecedented rate, so if they don't do anything
about it, the country will go into recession. When some researchers ask about a possible solution,
Tucker says that the only way to stop the spread is by conducting an inoculation program. Meanwhile
many infected waiters throw up right into the tea that they are going to serve to the guests. After
leaving the hospital, Carol notices a homeless guy having a seizure on the streets, but unlike the
terrified woman he’s being helped. When she makes it to her office, Carol is shocked to find Wendy’s
husband there, and he refuses to leave until he sees his wife. He also never shows any emotion as
he speaks. Carol calls Wendy to warn her and saves her from entering the building, so Wendy takes a
taxi to stay with her sister instead. Later that night, Carol reluctantly decides to let Oliver
spend time with Tucker since it’s his right as the father. On their way to Tucker’s house,
a terrified woman suddenly appears in the middle of the road, luckily Carol hits the brakes just in
time. The woman desperately asks for help as she insists that something terrible will happen soon,
but before she can add more details, a car suddenly runs her over. Carol notices the driver
still keeps a poker face during such a horrible accident, and when the cops arrive at the scene,
she immediately wants to testify against him. However the head cop simply tells her to go
home because they have this covered, which Carol finds weird. Moments later, Carol drops Oliver at
Tucker’s place, noticing her ex doesn’t show much emotion on his face before she leaves.
Afterward she meets Ben to attend a very fancy party, where they have a very philosophical
conversation with diplomat Belicec, his wife Ludmilla, and Doctor Yourish. After the party,
Ben takes Carol home and tries to kiss her, but Carol soon breaks the kiss because she doesn’t
want to ruin their friendship. Once inside, Carol sends Oliver a message and suddenly hears someone
at the door. She only opens it a bit and finds a man asking questions for the Census Department,
which doesn’t make sense at this hour. Carol tries closing the door in his face, but the man puts his
hand inside, triggering a struggle between the two of them. At last Carol wins and locks the door,
causing the man to go away. Meanwhile Oliver gets to play with his friend Gene, who says
his father is behaving weirdly, and Oliver thinks the same about his own. When he goes home, Oliver
finds Tucker making a special drink for him. The next morning, Carol notices lots of people on the
streets have blank stares on their faces, almost as if their soul has been taken away. When she
reaches her office, she is shocked to learn that all her clients have canceled their appointments
for the day. Carol tries to call Wendy but her husband picks up, saying that everything is fine.
This makes Carol think about all the things she’s been seeing and realizes the virus is controlling
people. When she begins googling some information on it, she’s suddenly startled by her secretary,
who offers some tea. Before she can drink it, Carol gets a call from Ben, who informs her
that the test results of the strange skin patch are ready. Carol immediately goes to the lab,
where Stephen explains that the skin sample is made up of several molecular spores that take over
the human brain during sleep and alter the genetic code, rendering a person unstable. This means that
in order to prevent the deadly infection, they are forbidden from sleeping until they find a cure. At
that moment, Ludmilla calls Ben to tell him that Yourish has been acting strangely. This causes the
trio to immediately rush to his house, and Carol notices the long lines on the streets where people
are waiting to get vaccinated against the new virus. When they make it to Yourish’s, they find
him in bed with his body going through a grotesque transformation. Carol tries taking a picture of
him but suddenly the monster-like man wakes up and attacks her. Ben quickly pushes Yourish away,
causing him to drag his body away before vomiting a weird liquid and dying. Afterward Carol is too
worried about her son possibly being exposed to this mess and rushes to Tucker’s house to pick up
Oliver. When she arrives, she finds Tucker in a meeting with his associates and immediately
asks about her son. Tucker says that Oliver is playing at Gene's, but Carol doesn’t believe him
and starts looking for Oliver around the house. At that moment, the men from the meeting surround
Carol, who gets scared and tries to run, but Tucker quickly tackles her to the ground and
infects her with his saliva. Fortunately Carol manages to push him away and runs through the back
door to escape. She tries asking the neighbors for help, but they’re infected as well. Then she gets
to her car, only to find the road blocked on every side and she ends up crashing. When she gets out
of her car, she is chased by a group of infected people, so she reaches the main avenue and tries
to ask for help. Everyone ignores her, so she decides to enter a subway station. Carol gets on
the train and finds it full of passengers with the same vague expressions. At that moment her phone
rings and she sees a message from Oliver, who asks her to save him because Tucker has hidden
him somewhere. This puts Carol on the edge of a breakdown, and one of the passengers reveals
he isn’t infected: everyone there is acting emotionless so the infected people will ignore
them, and he advises her to do the same. Suddenly, a group of infected people enters the wagon, so
Carol and the other sane passengers run to the end of the train and close the door. The infected ones
press the emergency button to make the train stop before breaking down the door to start infecting
the passengers, so Carol opens the back door and jumps off the wagon, escaping by running through
the tunnel until she reaches the locker room of a station. There she finds a guard’s gun, and when
said guard approaches her, she gets too scared and shoots him by accident. Terrified, Carol drops the
gun and crosses the station, keeping a poker face to pretend to be infected. When she makes it back
to the street, she watches some cops catching the uninfected citizens to force them to take
the vaccine, which is actually Tucker’s trick to pass the virus to everyone. At that moment
an uninfected cop notices the sweat on Carol’s face and tells her to go away quickly because
the sweat will give her away. Carol starts walking away and bumps into her neighbor, who offers the
shot to her. Luckily Carol’s acting convinces her that she’s already gotten the vaccine. Afterward
Carol goes to Tucker’s house, only to find it empty. She leaves a message for Oliver before
going out again, and she finds a bunch of people watching a couple end things for themselves. Carol
makes sure not to react and keeps going until she reaches the Belicec mansion, where Ben and Stephen
are still conducting some tests. After a bit of discussion, Ben decides to help Carol find her son
while Stephen and his assistant prepare to travel to Fort Detrick in Maryland to find a cure for the
virus. They also decide to stay awake, fearing that they might have been infected if they fall
asleep. At that moment Belicec comes back and Ludmille receives him with a hug, but Belicec
is infected and worried about potential intruders, so he lets a bunch of guards get inside. Luckily
Carol and the others see this on the security cameras and escape through the back door. When
they reach the streets, they notice Wendy being forcefully taken away by infected cops. She tries
fighting against them, yelling that she slept yet she was still ok, but the cops knock her
out anyway. After the group splits, Carol and Ben chat about Wendy’s words and deduce that Wendy has
somehow developed an immunity to the virus. Then the duo finds a dead cop on the ground,
so they steal his car and go to Carol’s office, where they begin searching through Wendy’s medical
profile. Ben finds out that Wendy was suffering from a brain illness called encephalitis,
and that’s why she’s immune: the virus only tends to attack healthy brains so that it can feed and
multiply its number. Ben calls Stephen at the lab to give him this new information while Carol
gets another text from Oliver mentioning that he’s being held at his grandmother’s home in
Baltimore. Scared, Carol confesses to Ben that she has already been infected with the virus,
but Ben promises that everything will be alright. Afterward, Ben drives like a maniac to the city,
crossing blocked roads until he has no choice but to let Carol go so the police will chase him
instead. Carol continues on foot, and when a cop stops her, she presents her ID with a poker face
and is allowed to leave. Eventually Carol reaches the station and boards the train to Baltimore,
where she hides in the bathroom. The lack of sleep is starting to take its toll on her and she starts
having visions, like seeing a second self in the mirror that wants to attack her. She wakes up just
in time and after washing away a piece of that strange flesh, she opens the door to find Gene,
who explains he lost his family and now he’s part of hers. He keeps asking her to sleep,
and Carol pretends she’ll do exactly that but in private. Once the train reaches Baltimore,
Gene checks on her again and finds her removing more flesh pieces from her body, so he stays
suspicious. Tucker comes to escort Carol and Gene to his mother’s place, believing Carol’s
emotionless act. Oliver isn’t around, but Carol continues to act around the family, and when she
gets a call from Ben, she talks in code pretending it’s her secretary. When Tucker finally leaves for
work, Carol uses the opportunity to search the house and finally finds Oliver in a room. The
two of them hesitate at first, but once Carol says a couple of emotional words to confirm she’s fine,
they reunite with a hug. Oliver mentions that he’s been sleeping every day but still hasn’t
transformed, and Carol realizes the medications for his sleeping disorder have made him immune.
Suddenly Gene catches them red-handed, but Carol easily pushes him away and rushes out with her
son. On their way out, Tucker sees them through the window and immediately goes after them,
starting a chase through the streets. Oliver finds a broken window in an abandoned warehouse and they
hide there, but Tucker comes inside too. While he monologues like a bad villain, Carol tries to
sneak to the door, but Tucker catches her from behind and tries to knock her out. Oliver cuts
in and hits his dad with a metal tool, so Tucker captures him instead. This gives Carol the chance
to hit him on the head and knock him out, allowing them to escape. Afterward Carol and Oliver hide
inside an empty department store. Carol searches the medicine section and finds an injection,
which she shows to Oliver as she explains she wants him to inject her heart with it if she
ever falls asleep. Then they go looking for some food and Carol gets a call from Ben, who learns
about their location and promises to pick them up soon. While his mother’s busy on the call, Oliver
slowly approaches a door with blood splattered nearby, but luckily Carol stops him before he can
open it. Instead she goes inside herself and finds multiple people on the ground going through the
transformation. The group includes a cop, so Carol very carefully comes closer to take his gun before
rushing outside and locking the door, telling Oliver to stay away from it. Hours start to pass
while they wait for Ben, and while Oliver sleeps, Carol desperately searches for anything she can
use to stay awake, going back to the beginning of the story. Unfortunately this isn’t enough and
Carol falls asleep anyway. Eventually the infected people inside the room wake up and begin hitting
the door as they try to get out. The noise wakes Oliver up and he discovers her mother has fallen
asleep, so he immediately injects her with the syringe, which wakes her up and cancels the
transformation just in time. Then Carol washes the weird flesh off her face and leaves the bathroom
to discover Ben has finally arrived. She rushes to hug him, only to realize he’s been infected
too. Carol backs away as Ben invites Carol to join the ‘new society’ that will have no crime,
hate, or discrimination. A terrified Carol points her gun at him, but Ben still opens the door and
lets out all of the other infected people before mentioning that they hate immunity as he points
at Oliver. The group tries to capture the child so Carol begins shooting quickly, killing them
one by one. However she can’t bring herself to kill Ben, so she just shoots him in the leg and
runs away with Oliver. Outside, they take Ben’s car to escape. While Carol drives like crazy,
she gets a call from Stephen, who gives her an address where a helicopter will be waiting
for them. When she reaches the main street, she finds herself surrounded by cars and she crashes,
causing her to lose consciousness. Lots of infected people now surround the car and
Oliver locks the doors before shaking Carol until she wakes up. A man manages to break a window but
before he can infect them, Carol speeds up and pushes the people away to escape. There are still
a few crazy ones hanging on the roof of the car, so Carol drives like a maniac and hits things on
purpose to make them fall. There are also police cars hitting hers until they make her crash,
sending the last few attackers flying against a shop window. Luckily the car is fine and
Carol keeps driving while getting directions from Stephen through the phone. An affected man throws
a Molotov bomb at her car, but Carol still drives with the vehicle on fire, not stopping until they
make it to the parking lot of the right building. The car crashes against a pillar, so Carol and
Oliver go out and run to the elevator, where they’re almost reached by the enemy. They hit
them and push them away, allowing for the doors to close. The duo finally makes it to the roof,
where Stephen and his army buddies rescue them in a helicopter. Sometime later,
scientists outside the USA have finally created a vaccine, and thanks to it the alien virus has
been eradicated from the entire world, allowing life to be normal again. As the main scientist
behind the vaccine, Stephen explains to the press that the vaccinated people will have no
memories of the earlier events. Meanwhile Carol has adopted Gene and she is now in a relationship
with Ben. While the boys leave for school, Ben reads the newspaper and comments on the
violent crimes committed by people, which leaves Carol thinking about the alien’s offer of peace.