A married couple Josh (Patrick Wilson) and Renai (Rose Byrne), their sons Dalton (Ty Simpkins) and Foster (Andrew Astor), and infant daughter Cali have recently moved into a new home. One night, Dalton is drawn to the attic when he hears creaking noises and sees the door open by itself. He falls from a ladder while investigating and sees a figure in the shadows. Hearing his terrified screams, Renai and Josh rush to his aid and declare the attic "off limits" to the children. The next day, Dalton falls into an inexplicable coma.
After three months of treatment without result, Renai and Josh are allowed to take Dalton home. Soon after, paranormal activity begins to occur; Renai begins hearing voices over the baby monitor when no one is in Cali's room, Foster says that Dalton sleepwalks at night, Renai sees a frightening figure of a man in Cali's room, who vanishes when Josh comes and the burglar alarm is repeatedly triggered for no reason with the front door open. After Renai finds a bloody hand print on Dalton's bed, she questions Josh about the house, but he ignores her. That night, Renai is attacked by the figure from Cali's room, and the Lamberts decide to abandon the house and move elsewhere.
In the new house, Renai sees the ghost of a dancing boy who leads her to Dalton's room. Josh's mother, Lorraine (Barbara Hershey), visits them one day, and says she had a dream in which a figure in Dalton's room replies "Dalton" when she asks what it wants; at the same time, she sees a monstrous red-faced demon standing behind Josh and screams, while Dalton's room is ransacked and Dalton himself is found lying on the floor.
Lorraine calls demonologists Elise Reiner (Lin Shaye), Specs (Leigh Whannell), and Tucker (Angus Sampson). Upon entering, Elise senses a presence in the house and upon entering Dalton's room, she sees something on the ceiling; to which Specs draws the demonic, red-faced figure Lorraine saw.
Elise explains that Dalton is not in a coma; he was born with the ability to travel mentally to the astral plane. He has traveled too far and become lost in a purgatory realm called "The Further", a place inhabited by the tortured souls of the dead. Without his mental presence, Dalton's body appears comatose and spirits can use it to enter the physical world. Josh is skeptical until he realizes that all of Dalton's drawings are of the demonic entity drawn by Specs.
Elise performs a seance to communicate with Dalton, but they contact the demon who threatens them before using Dalton's body to attack them until it is stopped by Elise. She reveals that her acquaintance with Lorraine is decades old, because she previously performed the same service on Josh when he was eight years old (he was terrorized by the parasitic spirit of an old woman). Josh also possesses the ability to astral project, and Dalton inherited this trait from him. Elise tells Josh that the only way to rescue Dalton is to go into the Further.
Elise puts Josh in a trance and he is able to project himself to their previous house. He goes to the attic and finds a red door, but is attacked by the mysterious figure that attacked Renai. After defeating him, Josh enters the Demon's lair, where Josh finds Dalton chained to the floor. After a tearful reunion, Josh frees him, but they are caught by the demon. Josh tries to fight it, but they are forced to flee with the demon in pursuit. Returning through the red door, Josh confronts the old woman that haunted him as a child. The old woman dissolves into darkness after Josh shouts at it to leave him alone. When Josh and Dalton return to their bodies they wake up in their new home and the spirits seem to disappear.
As they celebrate the apparent end of their ordeal, Elise starts packing her equipment with Josh, when she senses that something is wrong (she notices Josh's hands look old and dirty, similar to the old woman's), and proceeds to take a photo of Josh. Josh goes into a violent rage, as he doesn't like to have his picture taken and strangles Elise to death. Renai is horrified when she discovers Elise's dead body and searches for Josh to inform him of her sudden death. Renai picks up the camera and sees that the image Elise took of Josh is the old woman that haunted him as a child, implying that Josh has been possessed. Josh suddenly puts his hand on her shoulder, says Renai, I'm here, and she turns around and gasps.Patrick Wilson as Josh Lambert
Josh Feldman as Young Josh
Rose Byrne as Renai Lambert
Lin Shaye as Elise Rainier
Ty Simpkins as Dalton Lambert
Barbara Hershey as Lorraine Lambert
Leigh Whannell as Steven "Specs"
Angus Sampson as Tucker
Andrew Astor as Foster Lambert
Heather Tocquigny as Nurse Kelly
Corbett Tuck as Nurse Adele
Ruben Pla as Dr. Sercarz
John Henry Binder as Father Martin
Joseph Bishara as Red-Face Demon
J. LaRose as Long Haired Fiend
Philip Friedman as the Old Woman
Kelly Devoto and Corbett Tuck as Doll Girls
Ben Woolf as Dancing Boy
Lary Crews as the Whistling Ghost Dad
Jose Prendes as Top Hat Guy
Caslin Rose as the Ghoul / Contortionist
The movie was somewhat of a reaction of Wan's to the success of the Saw series. Wan directed the first Saw film in 2004, and while he stated in an interview with Entertainment Weekly that he was "very proud" of the movie, he also felt that the movie, specifically, the violence and gore of it, put some people off and made them hesitant to work with him. Wan thus made Insidious in part to prove that he could make a movie without the level of violence found in the Saw series.
Principal photography for Insidious was completed over the course of three weeks in 2010, from late April to mid-May at the historic Herald Examiner Building in downtown Los Angeles. In regards to the shorter shooting schedule, actor Patrick Wilson explained, "We had long days and a lot of pages a day, and we didn’t get a lot of coverage or rehearsal. But luckily, the benefit of doing a movie that’s not on a big budget—and the reason it’s usually done like that—is so if the filmmakers feel like, ‘OK, we’re not going to sacrifice anything on screen,’ which I don’t think they have, it lets them have complete control. So we were in good hands."
The musical score to Insidious was composed by Joseph Bishara, who also appears in the film as the demon. Performed with a quartet and a piano, a bulk of the score was improvised and structured in the editing process, although some recording sessions began prior to filming. On describing the approach of the film's soundtrack, director James Wan explained, "We wanted a lot of the scare sequences to play really silent. But, what I like to do with the soundtrack is set you on edge with a really loud, sort of like, atonal scratchy violin score, mixing with some really weird piano bangs and take that away and all of a sudden, you’re like, 'What just happened there?'"
An exclusively digital soundtrack album was released by Void Recordings on October 11, 2011. Additional songs featured in the film include:"Tiptoe Through the Tulips" by Tiny Tim (1968)
"Nuvole Bianche" by Ludovico Einaudi (2004)
"Black Angels" by George Crumb (1971)
The first promotional clip from Insidious was released on September 14, 2010. The following December, production company IM Global released an image and sales poster for the film. On January 22, 2011, FilmDistrict released the first teaser trailer for the film. Less than a month later, the film's theatrical trailer was made available online via daily entertainment news site Blastr.
Insidious had its world premiere in the Midnight Madness program at the Toronto International Film Festival on September 14, 2010. Less than 12 hours after its screening, the US distribution rights to the film and the worldwide distribution rights to any possible sequels were picked up by Sony Pictures Worldwide Acquisitions. On December 29, 2010, it was announced that the film would be released theatrically on April 1, 2011 by the then-relatively new film company FilmDistrict. The film was also screened at South by Southwest in mid-March 2011.
Insidious was released on DVD and Blu-ray on July 12, 2011 through Sony Pictures Home Entertainment. The Blu-ray bonus content includes three featurettes: Horror 101: The Exclusive Seminar, On Set With Insidious, and Insidious Entities. On the day prior to the film's home media release, Sony Pictures and Fangoria hosted a free screening of the film at the Silent Movie Theater in Los Angeles followed by an interactive Q&A with director James Wan and screenwriter Leigh Whannell.
The film opened with $13,271,464, making it #3 at the domestic box office behind Hop and Source Code. It has since grossed a total of US$54,009,150 domestically and US$43,000,000 internationally, for a total of $97,009,150 worldwide. Insidious was the most profitable film of 2011.
Review aggregate Rotten Tomatoes reports that 66% of critics have given the film a positive review based on 164 reviews; the average score is 6/10. The critical consensus is: "Aside from a shaky final act, Insidious is a very scary and very fun haunted house thrill ride." Roger Ebert gave the film 2 1/2 stars out of 4 and said, "It depends on characters, atmosphere, sneaky happenings and mounting dread. This one is not terrifically good, but moviegoers will get what they're expecting."
A number of negative reviews reported that the second half of the film did not match the development of the first. Mike Hale of The New York Times wrote that "the strongest analogue for the second half of Insidious is one that the filmmakers probably weren’t trying for: it feels like a less poetic version of an M. Night Shyamalan fairy tale." Similarly, James Berardinelli commented, "[i]f there's a complaint to be made about Insidious, it's that the film's second half is unable to live up to the impossibly high standards set by the first half." Ethan Gilsdorf of The Boston Globe wrote that "[t]he film begins with promise" but "[t]he crazy train of Insidious runs fully off the rails when the filmmakers go logical and some of the strange gets explained away as a double shot of demonic possession and astral projection."
Positive reviews have focused on the filmmakers' ability to build suspense. John Anderson of The Wall Street Journal explains "[w]hat makes a movie scary isn't what jumps out of the closet. It's what might jump out of the closet. The blood, the gore and the noise of so many fright films miss the horrifying point: Movie watchers are far more convinced, instinctively, that what we don't know will most assuredly hurt us... Insidious establishes that these folks can make a film that operates on an entirely different level, sans gore, or obvious gimmicks. And make flesh crawl." Michael Phillips of the Chicago Tribune wrote: "director James Wan and screenwriter Leigh Whannell admire all sorts of fright, from the blatant to the insidiously subtle. This one lies at an effective halfway point between those extremes." Peter Travers of Rolling Stone commented: "Here's a better-than-average spook house movie, mostly because Insidious decides it can daunt an audience without spraying it with blood." Christy Lemire of the Associated Press stated: "Insidious is the kind of movie you could watch with your eyes closed and still feel engrossed by it."
A sequel, Insidious: Chapter 2, was released on Friday, September 13, 2013. In November 2011, it was reported that Sony Pictures had registered online domain names for a second film.
A prequel, Insidious: Chapter 3, was released on June 5, 2015 to a high box office gross and a mixed critical response.
Insidious: Chapter 4 was announced in May 2016 for a release date of October 20, 2017 and a sequel to Chapter 3. Whannell will return to write, Adam Robitel will direct, and Blum, Peli and, Wan will produce. Shaye will reprise her role as Elise Rainer. Later it was announced that the films official title is Insidious: The Last Key.