Insidious: The Last Key (2018): Cast, Plot and Ending Explained

The full plot of Insidious: The Last Key runs from a 1953 childhood trauma to a family reunion inside the Further, and it ends on a phone call that leads into the first film.

In the prologue, Elise's harsh father, Gerald, punishes her for seeing ghosts. In the basement she accidentally lets a demon called KeyFace out through the red door, and the demon kills her mother, Audrey.

In the present day Elise takes Ted Garza's call and finds that his haunted house is the home where she grew up. She goes back and uncovers a hidden room in which Ted has been holding women captive. KeyFace then attacks her family, and her niece Melissa is left in a coma. Elise is also dragged into the Further, the spirit realm where the demon keeps the souls he has taken.

There she learns that KeyFace controlled both her father and Ted, and that he fed on the fear of their victims. Elise, her niece Imogen and her team fight their way through the Further. On the way they pass through a red door and briefly see a boy named Dalton in his bedroom, a quiet nod to the family at the center of the first film.

Gerald's spirit gives his life to protect Elise. Audrey's spirit helps the group escape, Melissa wakes up, and Elise makes peace with her mother's spirit and with her brother Christian. The closing scene is a phone call from Lorraine Lambert, who asks for help with her grandson Dalton.

The ending of Insidious: The Last Key closes Elise's personal story and then hands off to the first film, and in my opinion it is the neatest piece of series bookkeeping in the saga.

What actually happens? Elise and her allies escape the Further with help from her mother's spirit. Her father dies protecting her, and KeyFace's hold on the souls he trapped is broken. Melissa recovers, and Elise reconciles with her mother's spirit and with her brother Christian.

Why does Gerald's sacrifice matter? It could be argued that the film wants the audience to see him differently once the demon's control is revealed. KeyFace used both Gerald and Ted Garza, so the man who punished young Elise for seeing ghosts was also a puppet of the thing she let out. Gerald dying to protect her does not erase what he did, but it gives the Rainier family a resolution that horror sagas rarely bother to offer.

What is the Dalton glimpse? As the group moves through the Further they pass through a red door and briefly see a boy named Dalton in his bedroom. Whannell told TheWrap that the idea of red doors as openings between planes of existence was not planned for the first film and came from later writing. Seen that way, the door is a retcon dressed as a callback, and it works because the series had already built the Further as a place with its own geography. The Further page covers how that world has been described across the films.

What is the final call? Elise answers a phone call from Lorraine Lambert, who asks for help with her grandson Dalton. That call leads directly into Insidious (2011). It is an explicit bridge rather than a hint, and perhaps the only complaint is that the tidiness takes some of the mystery out of the Lambert case, but as a link between films it does its job.