The movie opens with a creepy monologue from an unknown woman. She claims that everyone dies, but some deaths are so shocking that they are forever carved into our memories. There is a place where all these horrors are carved, as the dead want their stories to be known.
The movie then cuts to a bookseller, who is busy arranging books on the shelves. Suddenly, he is approached by a thug named Bennet, who comes after him with a knife. Turns out he owes Bennett money, and hasn’t been able to pay for a long time.
In a last ditch attempt to save himself, the bookseller informs Bennett about a rare book worth millions and gives him the location. But despite this, Bennett still eliminates him by slashing his throat. The thug then gets out of the store, and he tells his accomplice about the rare book called “The Book of Blood”.
Meanwhile, we see the dead storekeeper with a smile on his face, indicating he sent Bennett on a dangerous mission. Following this, we see the name ‘Jenna’ carved on someone’s bloody skin. The scene then shifts to a young college student, Jenna, who lives with her parents in a luxurious house located near the sea.
She appears to be recovering from depression caused by a past incident involving her friend. Her mother encourages her to open up, but Jenna likes to keep her inner thoughts to herself. During dinner, we learn that Jenna is easily irritated by normal sounds like chewing, water dripping and laughing.
In order to distract herself from the sounds, she often uses a noise canceling headphone. At night, Jenna overhears her parents planning to send her to a rehabilitation center, hoping she can get back on track and behave normally. After knowing about their decision, she decides to leave the house and run away.
At midnight, when her parents are asleep, she sneaks into their bedroom, and steals some money kept inside the safe. She packs her clothes, and heads straight to the bus station. Since she has nowhere to go, she asks for a ticket to Los Angeles.
However, while getting out of the station, Jenna notices a strange man in black staring at her. She quickly walks away and gets on the bus. During the journey, Jenna is irritated by various sounds of people eating behind her seat.
She puts on her headphones, but her paranoia doesn’t end as she sees strange things inside the overhead compartment. After a few hours, the same man in black enters the bus and takes a seat. This freaks Jenna out, so she immediately gets off the bus at the next stop.
While walking around aimlessly, she is nearly taken out by a fast-moving car. Jenna then enters a cyber café, and searches for nearby accommodations; she doesn’t have many options so she books a cheap place. In the next scene, Jenna arrives at the large homestay.
She is warmly welcomed by the owners; an old couple named Ellie and Sam. Jenna then goes to her room, and she is approached by a young man, Gavin, who’s also a guest in this home stay. They then have a casual chat before going their separate ways.
Late at night, while Jenna is about to go to bed, she suddenly hears some strange sounds coming from the walls of her room. When she goes to inspect, she finds a cockroach oozing out of it, and this is when Ellie arrives in the room. The old woman calms Jenna down, and invites her to have some tea and cake.
Later, Ellie reveals that she used to be a registered nurse while her husband; Sam, is a carpenter. But then, as four of them are engaged in conversation, a large cockroach emerges from the floor. Ellie grabs it in a piece of cloth and gently throws it away.
Sam then claims that their house has a roach problem, but they will fix it soon. After the gathering ends, Jenna reveals to Sam that she is suffering from a condition called misophonia, which means that she’s easily triggered by sounds. She sometimes wishes that she was never born at all.
Hearing her depressing talk, Gavin asks her out for coffee the next day, to which she agrees. They exchange their numbers and decide to meet tomorrow. Unfortunately, when Jenna goes to bed, she suffers from sleep paralysis.
She then sees a haunted version of her mother drinking wine. Moreover, Gavin shows up and tries to have intercourse with her. Then, the old couple measure her for some ritual, while Jenna sees the same man in black creepily peeking at her through the window.
Soon after, she vomits hundreds of cockroaches from her mouth, and it turns out everything was just her nightmare. In the morning, Jenna goes to a nearby cafe to have a coffee with Gavin. She waits for him for a few minutes, but strangely, he doesn’t show up.
At this moment, she again spots the creepy man in black staring at her. Realizing that she’s being followed, Jenna quickly escapes the place through the back door. She then returns to the homestay, and confides in Ellie about her mental illness.
In response, the old woman consoles her, and suggests she stay here for a few more days to freshen up her mind. Ellie also shows her around the garden, and gently introduces her to different plants. Later at night, Jenna again hears some scratching sounds coming from the wall of her room.
She takes a closer look into the wall, and discovers a secret cabinet. And then upon opening it… she is shocked to find a zombie-looking woman inside with her eyes and ears stitched. Ellie knocks at the door, while Jenna gets a text message from Gavin, so she urges him to call the cops.
But what she doesn't expect is that it turns out Ellie is the one messaging from his phone. Just then, the zombie-woman grabs Jenna’s hair through the wall, so Ellie inquires if everything is fine. Here Jenna realizes that she needs to get out of here, so as soon as Ellie enters the room, she knocks her out with a strike to the head.
Jenna approaches each and every door inside the house, but all of them appear to be locked. Desperate to get out of the house, she starts observing the walls, until she finds a secret path. Jenna then enters the dark room without thinking, only to come across several zombies-like people kept inside.
Fortunately, she somehow manages to escape, and reaches the ground floor, but as she tries to exit, she is confronted by Sam. Ellie then knocks Jenna out by injecting her with a sedative. When Jenna wakes up, she finds herself confined to a chair; she can see and hear everything but can't move.
Ellie reveals that many years ago, her daughter’s family decided to move out of the house, but she didn’t let them do so. In order to keep them staying, the couple made them paralyzed, and kept them inside the wall, and under the floor in a way that they thought it could provide a better life for them. Poor Gavin is the latest victim, and we see him trapped in a corner somewhere.
Ellie claims that she is helping these people from the cruel world. The couple regularly feeds them, making sure they’re still alive. Now, it is her turn to be paralyzed and placed inside the wall; Ellie injects Jenna with a catatonic syringe in her eye in order to seal her eyes.
But when she is about to pull her eyes out, someone knocks at the door. Ellie goes to the door, only to find the same man in black. He brings out a picture of his son with Jenna, and inquires if she’s here.
He also reveals that he has been following her everywhere as he wants to talk with her. Ellie responds that Jenna left a few hours ago, but she invites the man inside for some tea. Following this, the man reveals that his son, Tony, and Jenna were a couple.
He has been searching for Jenna because she was on the call with Tony the night he died. Unfortunately, before the man can speak any further, Sam attacks him from behind and eliminates him. On the other hand, we see Jenna regaining her senses and trying to flee.
Somehow, she manages to crawl through the floor, and jump out of the window. She then enters the nearby shed, but immediately runs out after witnessing the mutilated remains of a man. With nowhere to go, Jenna gets into the man in black’s car and hides in the backseat when the couple shows up.
Sam loads the dead man in black in the same car and drives it away. Ellie follows him closely in her own car. After a while, they arrive at a secluded location which is on top of a hill.
Sam gets out of the vehicle, and manipulates it in such a way that it drives off the cliff. Unbeknownst to them, Jenna is still inside it, and she screams as the car plunges down the hill. In the next scene, we see another name, Miles, carved into someone’s bloody skin.
A blurry footage is then shown featuring a naked man inside a small room. All of a sudden, he begins experiencing something supernatural and the lights go out. The man’s terrifying screams are heard, and when the lights come back on, there are bloodied writings all over the walls, indicating that he met something evil.
A psychic researcher named Mary watches the video, and she regards the video as fake and doesn’t pay much attention to it. Later, we get to know that her only son, Miles, is suffering from cancer. When Mary goes to see him at the hospital, she finds her ex-husband outside.
Turns out this man left the family long ago, and Mary vehemently refuses to let him see his son. She goes to see her son, who is in his final stages. The poor boy only has one wish; he wants to be with his mother forever.
After a few days, we get to know that he has passed away, and despite the grief, Mary goes to work at her office. She then finds a guy named Simon waiting for her, and he reveals that he was the one who sent her the video tape a few days ago. Moreover, he is the same person from the video, and he claims to be the messenger of the dead.
Mary doesn’t believe in him and asks him to go away. However, when Simon claims that Miles sent him, she agrees to hear him out. The scene then cuts to several weeks later, and we see that the two have become a couple.
They have started a foundation which invites famous scholars from all over the world to see the dead talk. Following this, we are taken to a flashback. In one of their earlier experiments, Simon gets naked and goes inside an empty room.
As the guests watch from outside, Mary checks Simon thoroughly to see if he is hiding anything. Once the inspection is done, she gets out of the room and locks the door. Simon then warns them that the experiment can turn gruesome, as he is about to contact the dead.
The lights then suddenly go out and his desperate screams can be heard. And just like the earlier video, when the lights come back on, Simon is having a seizure on the floor, with blood inscriptions all over the walls. One of the messages appears to be from Miles, which says that he is not sleeping.
Mary is shocked to see this and believes that the message is from her son. After that, she starts showing interest in Simon and studies him more. When she takes him to her house, he goes straight to Miles’ room, and claims that the boy is here.
Mary is confused why her son is talking to a stranger rather than her, to which Simon gives a very vague explanation. The young man who appears in her life brings her hope and happiness, and she ends up being intimate with him. As the days pass, they continue their experiments and start a foundation.
Mary feels like she is closer to her son whenever she is with Simon. But one day, she unexpectedly catches Simon sleeping with a random girl. The drunk Simon inadvertently reveals that he is just a fraud who conned her.
He is not a messenger of the dead, and simply got to know about Miles through her ex-husband. He then explains that he conducted the experiment by rigging the room. Turns out Simon paid a maintenance guy to cut off the power for a few seconds.
For the messages, he actually wrote them the previous night using a chemical; this chemical stays invisible until it is exposed to an activating agent. And to make the seizures realistic, he injected himself with a microdose of penicillin, 1 hour before the act. Hearing all this, Mary is shattered, and she goes to her son’s room.
There, as she hugs his favorite toy, an invisible force suddenly starts writing on the nearby board; it says ‘bring him to us’. In the morning, a sobered up Simon approaches Mary, apologizes for his mistakes, and intends to leave. However, she asks him to proceed with the act, claiming there is a lot of money on the table.
Simon is shocked as he expected her to be angry, but he agrees to it anyway. The movie then cuts to the present, where Mary is having a meeting with a group of investors. She happily announces that Simon will give them a live demonstration about his abilities.
Simon then asks what she’s doing, as he’s not prepared for the act, but Mary tells her to just play along. She then leads him to Mile’s room, strips him naked, and locks the door, telling the audience that no matter what happens the door must be closed. All of a sudden, Simon sees the chair moving, and then ghost of Miles sitting on the chair.
Then, several other spirits show up, and begin attacking him. They brutally carve his skin, and write hundreds of messages on it. Simon pleads and screams to be rescued, but Mary chooses not to interfere, while the whole town falls into darkness in an instant.
When she finally opens the door, she finds a bloodied and half-dead Simon on the floor; his entire body is now covered with messages from the dead. We are then shown the name of Bennett written in blood, and the scene shifts back to Bennett and his accomplice, Steve. They are traveling to a place called Ravenmoor in search of “The book of blood”, and they nearly hit a girl, who turns out to be none other than Jenna.
As the duo is about to reach their destination, Steve warns Bennett that Ravenmoor is a haunted area, and that nobody dares to go there. However, Bennett, who is blinded by money, urges Steve to drive without complaining. Unfortunately, as soon as they enter the area of Ravenmoor, strange things start happening.
Their car battery inexplicably dies out, leaving them stuck. Bennett goes out to check the problem and during this, Steve notices the spirit of his mother. Without saying anything, he follows her to a nearby church.
Bennett goes after his friend, and soon finds him. Here, Bennett thinks he's praying, but turns out he's holding a gun at his throat. It is evident that he has been possessed by the spirit.
Terrified, Bennet gets out of the church, and then walks through the dark streets, until he reaches Mary’s house. The dust has settled on everything; it seems that no one has lived here for a long time. After a bit of looking around, Bennett hears laughter coming from upstairs, so he goes to Mile’s room, where he finds the now old aged Mary.
Simon is also there, and despite the terrifying situation, Bennett points his gun at her and demands the book of blood. However, she replies that Simon is the book; his entire body is carved with stories written by the dead. She further tells Bennett that he is not the first one to come here looking for the book, and he certainly won’t be the last.
At that moment, Bennett sees his name carved on the man’s body, right when he is attacked by a large number of feral rats. Bennett runs outside the house, and uses a knife to kill the rats which have entered his shirt. However, instead of killing the rats, he accidentally stabs himself several times.
Now heavily bleeding, he staggers across the streets, until he reaches Ellie and Sam’s house. Currently, the old man is handling Gavin’s body. Seeing this, Bennett doesn’t even know how to react, and Ellie attacks him from behind and kills him.
The scene then shifts to Jenna who is in the hospital, having survived the accident. The police tell her parents that they found her body alongside Tony’s father’s. Jenna’s mom then reveals that Tony and Jenna were in a relationship before he tragically passed away.
A few days later, Jenna is released from the hospital, but she is heavily depressed. One night, she starts reminiscing about the time spent with her ex-boyfriend. We are then shown a flashback of Jenna’s final conversation with Tony.
Both of them are mentally ill patients trying to recover themselves. In a shocking turn of events, it is revealed that Jenna was the one who instigated Tony to kill himself. They had a suicide pact, and Jenna claimed that she was also on top of a roof, just like him.
However, she was at home, unable to go through with it. Tony was also scared to commit the deed, but when she called him a coward, he went ahead and jumped off the building. At present, Jenna feels guilty for her actions and cries remembering it.
Fed up with what her life has become, she once again runs away from home and voluntarily visits the evil couple. She asks them to end her suffering, and they happily oblige. The couple then performs their experiment on Jenna, stitching her eyes and ears.
The movie ends as she is buried in one of their chambers. We can see a smile on Jenna’s face as she is finally rid of the damning noises.
