Insidious

Insidious is a 2011 thriller/horror film from the creators of Saw.

Josh and Renai Lambert have three children, the oldest being ten-year-old Dalton. As they begin to settle into a new home, they experience strange noises and other unexplained phenomena. Soon, Dalton is rushed to the hospital in a coma, suffering a severe head injury after falling in the attic. Months slip by, and the doctors still have no explanation for his continuing coma. When the boy is returned home under his mother's care, more frightening events occur in the home. The mother is so horrified that she moves the family to another new home in hopes of leaving the fearful memories behind them.

The family quickly discovers that the haunting has nothing to do with their home. The supernatural outpouring is coming from their comatose son. Several scientific experts, headed by psychic and demonologist Elise Rainier, observe the son, the family and their home. They determine that Dalton is trapped on the other side in a dark world they call The Further. The parents team with the scientists to try to bring their boy back from The Further and save him from the clutches of a dark entity that hopes to claim him as his own.

The film's success inspired three more movies: Insidious: Chapter 2 (2013), which continues the tribulations of the Lambert family; Insidious: Chapter 3 (2015), a prequel exploring Elise's past; and Insidious: The Last Key (2018), where we see Elise handle another case Before her fateful encounter with the Lamberts. A fifth film, Insidious: Fear the Dark, which tentatively would conclude the Lamberts story, is scheduled to be premiered in 2023.

Tropes used in Insidious include:

Alien Geometries: Accessible only through astral projection, way too big to be mapped and it takes minutes to travel miles.
Alternate Character Interpretation: The ghost of the old lady has been inhabiting Josh's body since when he was a child - that's why he sees the old woman in the mirror while in the further: being there reminds her of her true nature.
- That's probably more of a WMG than this trope.
Astral Projection: How Dalton gets lost in The Further, and Josh gets him back.
Badass Beard: Tucker, the tall paranormal team member, has one.
Creepy Good: Elise is a creepy old lady with Psychic Powers who talks about Things Man Was Not Meant to Know as if she's discussing the weather... but she's legitimately trying to help the protagonists save their kid from evil spirits.
Cruel Twist Ending
Demonic Possession: With Dalton's mind elsewhere, it leaves his body open to this. Josh as well.
Downer Ending: Josh is possessed by an old woman from The Further he encountered as a child and kills Elise, and presumably Renai.
- The Bad Guy Wins
Genre Savvy: To paraphrase Something Awful, "this is one of the few haunted house movies where the protagonists try moving."
Grandma, What Massive Hotness You Have!: Hello, Barbara Hershey.
Haunted House: Subverted. The Lamberts only think they have this problem.
Hey, It's That Guy!: Nite Owl is Josh.
The Further Is A Scary Place: It's full of the souls of the dead forced to relive their deaths. And it also leads to Hell.
In the Blood: Dalton's ability to astral project was inherited from Josh. His ability may have come from his mother.
Jump Scare: This film is filthy with them.
- On the DVD special features, in a short documentary called "Horror 101", the creators say they were specifically trying to avoid the conventional "jump scare" which comes out of nowhere, carries no suspense whatsoever, and has no real meaning or effect on the plot; all the jump scares in Insidious are quite carefully built up to, and all of them serve to further the story.
New House, New Problems: Actually happens twice, after the family tries moving.
Nice Job Breaking It, Hero: Seriously, nice one, Josh
Nightmare Fuel Coloring Book
Not Afraid of You Anymore Subverted
Nothing Is Scarier: And how!
Offscreen Teleportation: Done by the Smiling Family.
Our Demons Are Different
Scare Chord: Plenty of them.
- Composed by the same guy who played the red-faced demon.
Shout-Out: In a scene where we see Josh behind his teacher's desk in the classroom, the face drawn in chalk on the blackboard is the puppet from Saw.
- In the scene where Elise tries to make contact with a dreaming Dalton, the gas mask she puts on looks exactly like the one used by Dream of the Endless.
Slasher Smile: A few of the spirits have them, most notably the Doll Girls.
Soundtrack Dissonance: "Tiptoe to the window, by the window, that is where I'll be, come tiptoe through the tulips with me..."
Spooky Photographs
Spooky Seance: Elise convinces the family to try this so she can bring back Dalton's spirit.
Supernatural-Proof Father: at first. Later it is revealed that the reason he was ignoring the evidence was that he too was haunted.
Title Drop
Too Dumb to Live: Josh... twice in a row. Before entering the Further he was very clearly told that he must act stealthy. Of course, once inside he questioned every being he met. So much for being stealthy. Then once back in his house, before going back to his body, he met the Old Lady that tried to possess him when he was 8. With not much time left, he chose to yell at her (while she wasn't in any position to do something harmful against him or someone he cares) instead of continuing his way. In the end, the few seconds he lost prevented him to come back in our world, and lead to Elise (and possibly Josh's wife)'s demise.
Trailers Always Spoil: "It's not the house that's haunted, it's your son."
Wolverine Claws: The Big Bad has them.
X Meets Y: Poltergeist meets A Nightmare on Elm Street.