Insidious (2011) is a supernatural horror film and the first installment in the film series of the same name. The movie is about a couple whose comatose son becomes plagued by ghosts who want to use the boy’s body as vessel.

The film starts with the couple, Josh and Renai, and their children, Dalton, Foster, and Cali starting a new life in their new home. While exploring their new house, Dalton sees a figure in the shadows and falls from the ladder leading to the attic. His parents rush to him and forbid going to the attic again. Dalton falls into a coma the next day.

After months of failed treatment, the couple bring the unconscious Dalton home. Then strange and supernatural things started happening to them and the couple is forced to find another home.

In their new home, Renai glimpses the ghost of a dancing boy who then guides her to Dalton’s room. Then Josh’s mom comes to visit and before she can tell her dream about Dalton, she sees a monstrous red-faced demon behind Josh. The woman screams, and things start happening in Dalton’s room, leaving the boy lying on the floor.

Josh’s mom seeks the help of the demonologists, Elise, Specs, and Tucker. Elise senses right away a presence, and she sees the red-faced demon on the celling.

Elise then explains that Dalton is not really in a coma but instead stuck in the purgatory realm called “The Further,” where the tortured souls of the dead remain. And because of his lost consciousness, spirits use Dalton’s body to enter the physical world. Josh accepts the truth when he sees that his son’s drawings resemble the demon sketched by Specs.

Elise performs a séance to reach Dalton’s consciousness but she is blocked by a demon who tries to attack them with Dalton’s body. Elise then confesses she has known Josh’s mother for a long time because Josh was also a victim of terrorizing spirit before. It turns out that Josh is also capable of astral projection, and they should use such ability to go into the Further in order to save Dalton.

Josh then goes into a trance with Elise’s help and projects himself to their former home. He reaches the attic and finds a red door, and he is attacked by a mysterious creature who also attacked his wife. Josh defeats the figure and fins his son chained in the demon’s lair. Josh cannot defeat the demon so he decides to just flee with his son. He also encounters the spirit who plagued him before. After confronting the spirit, Josh and Dalton wake up in their physical bodies, and the haunting spirits seem to have disappeared.

Afterward, Elise prepares to leave but notices that Josh’s hands are dirty. When she takes a photo of Josh, the man is enraged and kills Elise. Renai eventually finds Elise’s body and she sees that the image of Josh taken by Elise shows the spirit that haunted. Realizing that Josh has been possessed, Josh then appears and places his hand on her wife’s shoulder.