NOTE: This spoiler was submitted by Spectre.
The film opens with a quote:
"Two possibilities exist: either we are alone in the Universe, or we are not.
Both are equally terrifying."
Arthur C. Clarke
We cut to the house of Daniel Barrett (Josh Hamiliton) and Lacy Barrett (Keri Russell). They are having a barbecue with some friends. Their youngest son, Sam (Kadan Rocett) is tending to a lizard that has lost his tail. He claims he wants to nurse it back to health, but his parents think he is just toying with it. They are waiting for their oldest son Jesse (Dakota Goyo) to come home. Lacy calls him and Jesse claims to be in a session of Call of Duty with his buddy Kevin Ratner (LJ Benet). Daniel calls Kevin "Ratner" because he thinks he is a bad influence on his son.
We see Jesse with Kevin at his house. They are not playing video games. Kevin has put on a school girl porn. This makes Jesse uncomfortable.
Jesse bikes home quite late.
We cut to the family with their friends, the Jessop family. The adults gossip about work and other friends relationships while the kids mostly stay silent. However, Jesse seems to get some subtle flirtations with Shelley Jessop (Annie Thurman).
Later that night, Lacy is looking over stuff in bed when Daniel plops down and tries to make a move. Lacy tells him it can't be tonight as she needs to go over everything (she's a real estate agent). Money has been tight ever since Daniel lost his job as an architect.
Jesse and Sam talk to each other on walkie talkies as Jesse tells his brother the story about The Sandman. Sam asks if the Sandman will take his eyes. Jesse jokes that maybe he will, before saying that he is still young for that to happen.
Lacy gets up in the middle of the night and checks on the kids. She goes downstairs to find the refrigerator ransacked and the backyard sliding door open.
The next morning, Lacy and Daniel warn the kids to make sure that the door stays shut, but both deny opening it. Lacy wonders what animal would take certain food like lettuce but not eat the bacon. Daniel jokes that it must have been a giant bunny. Daniel asks the family to wish him luck as he has an interview for a job that morning.
At the interview, we find out why Daniel lost his job; the project he was working on ran out of funds and his team was let go. Daniel lies about wanting to make a change anyway. We then see him by his car as he slams his briefcase into his car in anger. It is clear that they are not going to hire him.
At home, he looks at the mortgage bill which is 90 days overdue. When Lacy comes by and asks about the interview, he lies and says he think he will get a call in a week.
Lacy wakes up again on another night. She checks the locks, and checks on her boys to see that they are still telling stories via walkie talkies. She tells them to go to bed.
Lacy goes back downstairs to find all the food in their kitchen stacked into weird tower shapes. The lighting in the room has made the tower make a weird circle shaped shadow. Lacy backpedals into Sam, who said he had a bad dream. Lacy asks if he did the towers, but Sam said The Sandman did it.
Daniel calls the police the next morning, but since there was no forced entry, there isn't much they can do. The officer notices the alarm system and Daniel admits they let their service run out to save money. The officer suggests they get it turned back on.
Lacy takes a meeting at a house she is trying to sell. It is a couple with a young daughter. The man has to take a call just as the little girl has an asthma attack. The mother gets her daughter to breathe into an inhaler and she calms down. Lacy tells the woman it gets better. She recounts how her eldest son Jesse used to be very sick when he was young but after a while he got to the point that he didn't get colds. The woman asks for Lacy's opinion on the house. Lacy says that though she should be selling her on the property (and she obviously needs the commission), Lacy is honest, and tells her that her family can do better than the house.
That night, Daniel comes clean to Lacy about the interview saying it actually didn't go well. Lacy is angry he lied, but Daniel said he didn't want to put more pressure on her. Lacy tells him not to make it about her.
Jesse and Sam can hear their parents fighting. Sam asks if their dad is going to leave. Jesse tells him everything is going to be fine.
The family is sleeping when the security alarm goes off. Daniel races downstairs with Lacy while Jesse watches over Sam. Daniel gets a call from the security company and resets the alarm. The company thinks it is a false alarm as the alarm stated that all 8 entry points were entered at the same time. The company says it will send out a technician tomorrow. Daniel hangs up and looks at Lacy, who is staring at the picture frames they had on the shelves. All the pictures have been removed.
Daniel calls the police again, but the officer still believes nothing is going on. He asks Daniel if any problems are happening at home; sometimes kids lash out in subtle ways when things are going bad. The technician from the security company tells Daniel that there was nothing wrong with the system.
Daniel and Lacy talk to the kids who both deny taking the photos. Sam mentions his Sandman dreams and how he took the photos. Lacy asks about The Sandman, but Sam won't reveal anything. "He told me not to say," Sam says.
Jesse asks Sam to come clean, but he denies taking the photos. Daniel is tearing apart Sam's room looking for them, but Lacy sides with her son and tells Daniel to calm down. He scratches at something behind his ear, saying it is a "bite." Lacy says they should take Sam to a therapist; she talked to the Jessop's and they know a doctor that works on a sliding pay scale. Daniel is shocked and angry that she mentioned their financial problems.
Daniel and Sam later go to the park. Sam goes to play soccer with some kids while Daniel talks to Mr. Jessop and denies their family problems. Suddenly he hears laughter. Sam has wet himself and the kids are laughing at him. Daniel comes over and says it's okay, but he should of said something. Sam stays silent for an uncomfortably long time then lets out a long, piercing scream.
Lacy is at the house, when she gets Daniel's call about Sam. She goes into his room and finds a drawing of Sam with a large slender figure. Lacy realizes it is The Sandman. Out of nowhere, a bird hits the window and dies. Lacy is horrified, but that becomes pure terror as hundreds of birds start slamming into the house in what looks like a mass suicide.
Specialists come by and collect the birds, afraid it is some kind of sickness infecting the birds, like Avian flu.
Lacy and Daniel ask Sam about his actions at the playground. Sam says he doesn't remember most of it. They look at each other and decide to get him a therapist.
Lacy wakes up again on another night. She checks on Jesse, then goes into Sam's room and sees an alien like shadow standing over his bed. She turns on the light to find the figure and Sam gone. She calls out for Daniel and they search for their son. Daniel sees him outside walking wearing only his underwear. Daniel shakes him, and Sam comes to asking why they are outside. Sam has had another fugue state.
Lacy says she saw someone standing over Sam's bed but Daniel says she was seeing things. What makes it even stranger is that Sam got out of the house without setting off an alarm. "Do you think I imagined it?" Lacy asks.
Daniel looks at the scab behind his ear. It is clustered around red dots.
The next day, Jesse breaks into the house his mother is showing via stealing the lock code. He brings Kevin, Shelley, and another friend and they have a party. Shelley and Jesse talk and Jesse stupidly tries to use a move out of the porn film he saw and grope Shelley. Shelley tells him to stop and he apologizes. Shelley asks if he has ever kissed a girl before and he admits he hasn't. They kiss. Jesse bikes home elated when he notices all the lamp lights going out.
Daniel has installed security cameras in the house. That way, if someone shows up they will know. Lacy asks if this isn't some weird way to spice up their sex life. "That wasn't my intention, but I like where your heads at," Daniel jokes, trying to bring some levity to the situation.
Jesse and Sam talk on walkies before bed. Jesse tells his brother he won't let anything happen to him.
Daniel sleeps at the computer desk to keep watch. The next morning, he rewinds the tape and notices that static happens in all the room at a specific time.
Lacy shows the house she's trying to sell to another couple who seem receptive on buying it. They look ready to close when Lacy seemingly has what looks like a stroke. She then walks to the glass door and starts slamming her head into it, causing it to crack. Lacy wakes up, the incident apparently a dream. She goes to the bathroom and sees abrasions on her scalp. She then gets a call from her boss, telling her that she had a breakdown in front of a customer. Lacy looks at her phone and realizes she can't recall the last several hours. Lacy's boss tells her to take some time off until she gets better. Lacy then gets a call from the bird specialist and tells her that while the birds were not infected, what is strange is they were from 3 different migrations and they all converged on their house.
Lacy begins to look up research, starting with the bird migration stories, to increasingly finding information on UFO's and similar occurrences to what they have been experiencing.
Daniel is at another company, and the boss there is more receptive to him. He tells Daniel the company loved his presentation, and they want to bring him in. Daniel thanks him.
Daniel comes home, with Lacy ready to tell him the bad news when he reveals he got a job that starts in two weeks, handing her champagne and flowers. Lacy hugs him, and Daniel says he is glad to give her good news for once, and that they should celebrate. Lacy decides to hold off telling him, deciding they both need a break.
Daniel and Lacy spend the night in bed together, truly happy for the first time in weeks.
Lacy wakes up to find Daniel out of bed. She goes downstairs to find the backyard door opened. She turns a light on to see Daniel outside. She calls out to him, and when he doesn't respond, she goes up to him, to see his mouth open in a silent scream. Lacy tries to snap him out of it, but suddenly he begins to bleed profusely out of both nostrils before reentering the house. Lacy runs after him, and Daniel immediately breaks out of his trance, asking why he is bleeding.
Lacy shows him the research she found, starting with the birds and ending with the UFO stuff. Daniel is skeptical, but Lacy then shows him the picture Sam drew that is eerily similar to the one another boy drew that disappear a few years ago. Daniel doesn't believe in the stuff and notes, "There has to be another answer."
The next day, the Jessop family take Sam to the pool. Sam doesn't want to take his shirt off so Shelley begins to before looking away horrified. Her mother takes a closer look only to see multiple bruises on his chest. Mrs. Jessop is startled by what she sees. She asks Sam who did this to him.
Jesse and Kevin are in the woods behind a golf course with an air soft gun. Jesse says he kissed Shelley and Kevin congratulates him, but tells him he has to go further with her since he does it with all his girls (Kevin is of course, obviously exaggerating). He then decides to be an asshole and chase Jesse into the woods, shooting him with the air soft. Jesse gets lost running, before hearing a screeching sound in his head. He covers his ears before apparently having a mass seizure, something Kevin notices.
Daniel and Lacy wait at the hospital. The doctor comes and tells them Jesse has a clean bill of health. They can't explain what caused his incident. However, there is more. They find numerous circle symbols all over his body. They were branded onto him, and Jesse denies doing it to himself. Lacy and Daniel look at the photos with tears in their eyes. The doctor explains that he automatically has to contact Child Protective Services, and they will have to do a follow up. Daniel thinks Kevin did it and violently confronts him. Kevin's father runs out and knocks Daniel out for attacking his son.
Lacy and Daniel are at home when Mrs. Jessop comes home with Sam. Tears brim in her eyes.
Lacy is a wreck trying to figure out what is happening to their family. Daniel tries to comfort her, but she pulls away. "DON'T TOUCH ME," She screams. She tells him that everyone is starting to think that they hurt their kids, that The Sandman is actual Daniel. Lacy pushes Daniel and asks if he has been beating their kids, but Daniel says he didn't do any of it.
Later that night, Daniel goes to check on Sam. When Sam rolls over, he has no eyes, startling Daniel.
Daniel wakes up. It was only a dream. He begins to look at the security footage during the static. Slowing the image down, he is able to see tall gray figures, in every room of the house standing over his family as they sleep.
Daniel goes to Lacy and recounts Jesse's birth and how he thought he was moments away from burying his child. Till now, that was the scariest time of his life, but he believes he got through it because he had her. "I'm ready to believe," Daniel tells her.
Lacy and Daniel set up a meeting with Edwin Pollard (J.K. Simmons), a lead expert in alien activity. Daniel notices all his paper clippings and numerous cats. Pollard tells them that he doesn't fight the aliens anymore. Lacy asks what he means. "The Grays," Pollard says. That is what he calls them. He shows them a book of three types of aliens, and notes that most people that claim to seen aliens see something like The Grays. He then proceeds to ask them a series of questions to determine if they have had a genuine encounter. Their illnesses, fugue states, and the bird incidents are enough to make Pollard believe they are serious.
"What is so special about us?" Lacy asks.
"Nothing," Pollard replies.
Pollard replies that he has interviewed thousands of people that have dealt with the same things they have, and they all came from different walks of life. Pollard continues saying people think that aliens will invade en mass and destroy the world and take the resources; that isn't true. They are already here. Studying us. Watching us. Pollard mentions that they probably have implants so they can be tracked. Daniel shows his "bite" and Pollard confirms it is a tracker. Lacy asks if they can remove it, but Pollard says he tried that before, and it just burrows deeper. He shows them his own tracker placement and how he tried to carve it out.
Lacy is in the bathroom, splashing some water on her face, obviously feeling sick from what she is being told. She notices another room and goes in.
Pollard tells Daniel that based on what they told him, they are experiencing the end of something. Daniel asks what. Pollard notes The Grays usually take a child. Pollard asks who apparently had contact first. Daniel says Sam.
Lacy sees the room covered in photos of dozens of missing children.
Daniel asks what they can do. Pollard says they need to fight back and unify their family. He has heard cases of families being able to repel the aliens away, so they go and target another family. Pollard warns them to take action since it is apparent they do not have much time.
Daniel goes and buys a gun. Lacy goes with Sam and gets a German Shepard. They begin to board up the house, bracing for an attack.
Daniel asks for Jesse's help, but Jesse think his dad is crazy and tells him he isn't a little kid anymore and that Daniel ruins everything. He bikes off to see Shelley. Shelley asks about what is going on. Jesse says if he told her, she'd think he is crazy. Shelley says she has known his father since she was a baby and while he was always a little crazy, she is willing to believe him. Jesse apparently tells her the truth, but we don't see it.
Lacy tells Sam that if The Sandman comes, he has to ignore him at all cost. Sam promises to.
The 4th of July. The family is eating dinner in the boarded up house. They can't go outside, so Daniel turns on the TV so they can watch fireworks. Daniel reminisces about Sam's first 4th of July. Sam remembers he thought the fireworks looked like ice cream. Jesse remembers his; how his father carted him up a hill to watch the show and his response was wanting to go home. They laugh at the stories, getting some much needed levity. However, moments later, the TV begins to flicker and pop and a bright white light shines through the boards. Daniel tells Lacy to get the kids upstairs while he grabs a shotgun. Lacy grabs a knife and takes the kids upstairs. The lights go dead.
Daniel points the gun at the backyard door, waiting.
Lacy puts them in one of the rooms and tells them not to open it for ANY reason. Lacy walks down the hallway, not realizing there is an alien right behind her. She goes into her bedroom where the TV is on and flickering. The door slams shut, trapping her inside. She screams for Daniel.
Downstairs, the bolts holding the boards up are being popped out by the aliens. The boards fall and a bright white light cascades into the kitchen. "LEAVE US ALONE!!!" Daniel screams, firing a round from the shotgun.
Sam and Jesse are in their room when they see the boards in their room becoming undone. The door starts to shake and break, but it is only their father, who gets them out of the room. They reach the master bedroom and bust it open. Now the family is together on the bed, looking around as several aliens surround them.
Jesse opens his eyes. His parents are gone, and Sam runs away. Chasing after him, the house melds into the one his mother was trying to sell. Jesse hears a pounding in the kitchen. It is his dad, tapping the shotgun on the floor as he sits next to his dead wife. "You're right," Daniel says, "I do ruin everything." Daniel then puts the barrel in his mouth and pulls the trigger in front of his son. Jesse hears Sam giggling and runs after him to walk down a long corridor. He opens a door to find Kevin and Shelley watching a porn telling him to join them. He turns around and sees Sam on the ground. He reaches for his brother when reality snaps back in. His parents and Sam are still on the bed alive, while he is surrounded by three aliens. They latch onto him and take him away.
3 MONTHS LATER
Pollard is looking at a newspaper when he sees the article about the suspicious disappearance of Jesse and how his parents are suspected of foul play. He cuts the article out for his collection.
The remaining family has moved to a smaller place. Daniel is talking to their lawyer, obviously having to go to court over Jesse's disappearance. They have mapped other child disappearances, obviously not giving up on finding their son alive.
Pollard adds Jesse's photo to his wall of missing kids.
Lacy brings Sam so more toys, and she sadly looks at photos of Jesse. She finds some old drawings, to see pictures of Jesse surrounded by aliens, and Jesse as a baby. Horror washes over Lacy's face as she remembers talking about Jesse's illness and how Pollard asks about unexplainable illnesses in the family. Lacy realizes Jesse was the true target of the aliens, having chosen him at birth.
Sam is looking into a box of toys, when his walkie talkie crackles to life. He picks it up with his mother looking on in shock. He responds back, calling for Jesse. Jesse responds back, calling Sam's name.
Fade to black.