The Quiet Ones (2014) is a psychological/supernatural thriller examining the thesis of a charismatic professor named Coupland (Jared Harris), who attempts to prove that supernatural forces do not exist, but that supernatural events are instead telekinetic expressions from the psyche of someone who has lived through extreme trauma. The professor and his research students study a girl named Jane Harper (Olivia Cooke), who manifests the spirit of someone named Evie through increasingly dark and threatening situations.

[Spoiler Alert] At the end of the film, two of the film’s characters are killed by apparent telekinetic events. Following their deaths, Professor Coupland attempts to kill Jane, believing that stopping her heart and resurrecting her with adrenaline would effectively eradicate the persona within. He’s stopped by Brian, the research group’s chronicler, who has a special bond with Jane.

Once Jane awakens, an invisible force shoves Brian out of the room, and Jane lights herself on fire as the door closes between the two. Moments later, a charred face lunges at the door, and the scene ends. The film’s final shot shows a disheveled-looking Brian, now in the care of a mental asylum, being accused of murdering everyone else in the group. He manifests smoke in his hand, and the film ends.

Does this ending imply Coupland’s theories were correct, or incorrect? There’s definitely an ambiguity in the take-away, as there are two chief ways to interpret the material.

In support of Coupland’s theory: Over the course of the film, almost all of the evil/demonic/terrifying things Jane does could be substantiated by Coupland’s theory that they are manifestations caused by Jane’s traumatic past. She throws objects around, generates fire, causes harm to people while not in their presence, etc. The one exception is the moment when a large, wet, tentacle-like object protrudes from Jane’s mouth during a particularly wicked summoning of Evie - a situation that seems far beyond the realm of Coupland’s logic. He, however, dismisses the incident as another manifestation of darkness and completely reasonable.

That scene could serve to tip the scales against Coupland being correct, but that’s for the viewer to interpret.

Brian speculated that Jane was possessed by the spirit of a dead girl named Evie Dwyer, who died in a fire she caused when her father, a cult leader, was planning to offer her as a sacrifice in hopes of resurrecting the demon Lillith. Coupland counters this, saying that story is simply something Jane heard about as a child and exists in the recess of her mind, which Jane is using as fuel for her manifestations. For this take-away of the film, we assume Coupland is correct.

At the end of the film, the mental trauma simply became too much for Jane. She telekinetically dispatched a few members of the research party, burned herself to quell the terror, but couldn’t bring herself to hurt Brian, who had only showed her compassion. The “demonic” figure in the fire that jumped at Brian in the penultimate scene wasn’t a demon, but a severely-burned Jane in her last moments of movement. Brian then began manifesting similar qualities, thanks to having endured his own trauma witnessing the brutal deaths of everyone else in the research group.

In contrast to Coupland’s theory: Everything that happened during the film was the result of Jane being possessed by a demon (the spirit of Evie Dwyer) as Brian speculated. All that she experienced was thanks to that possession, and at the end of the film, the demonic spirit jumped from her to Brian, giving him the same qualities.

The tentacle scene therefore was a demonic oddity, and the charred figure at the end of the film was representative of the demon escaping Jane’s body and entering Brian’s.

Either way you look at it, supporting evidence exists. The viewer should interpret whether or not Coupland was correct on their own.