WARNING: The following contains spoilers for The Possession of Hannah Grace, in theaters now.

The Possession of Hannah Grace revolves around a former cop, Megan (Shay Mitchell), who's suffering from PTSD and addiction, and embarks on a new career as a morgue assistant. She works the graveyard shift, taking photos, making notes and fingerprinting cadavers, until the job goes horribly wrong with the arrival of the body of Hannah Grace (Kirby Johnson).

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As eerie events begin to happen, Megan learns that Hannah died during an exorcism gone horribly wrong three months earlier. Yet, somehow, her body is "alive" and haunting the morgue. Megan realizes that whatever possessed Hannah's corpse didn't die when she did, which leads to a scary finale as Megan faces off against the demon within.

HOW TO KILL HANNAH

The Possession of Hannah Grace

With Hannah murdering people left, right and center, Megan gets in contact with her ex-boyfriend, police officer Andrew (Grey Damon). But as soon as he starts to warn her about the escape of a homeless man who was arrested after he broke into the morgue, the man shows up and abducts Megan. He takes her inside and reveals that he's Hannah's father, Grainger (Lewis Herthum), and that they need to burn his daughter's corpse.

He was the one who smothered Hannah to death when the exorcism didn't work in the opening scene, in order to save one of the priests. Grainger indicates that after they buried her, she escaped from the grave, and since then, he's been tracking her killing spree. When Megan points out that Hannah's body seems to be healing, Grainger confesses that the more she kills, the more she heals. Hannah was brought in after cops caught Grainger trying to mutilate her body, which led to him finally understanding the demon can only die once the corpse is destroyed.

THE DEMONIC SHOWDOWN

That leads to the duo recovering Hannah's corpse and attempting to burn it in the morgue's incinerator. However, the demon rises up, and Hannah burns her father alive instead. A wounded Megan escapes, but Hannah stalks her, feeding off her fear, as Megan suffers from depression just like Hannah (which made her susceptible to possession). Andrew eventually arrives to rescue Megan, but Hannah uses telekinesis to try to dismember him. In the fracas, Megan grabs his gun and shoots Hannah several times, including to the head.

It's poetic justice, as Megan's failure to use her firearm resulted in her partner's death months earlier, which is why she spiraled into depression. Now, however, Megan is reborn as she locks Andrew out of the morgue, and takes Hannah's body to the incinerator. As expected, it's an uphill battle, as the possessed girl fights back, grabbing Megan's face, and tries to drag her in. Eventually the heroine succeeds, and incinerates the body.

MEGAN'S FATE

The film's final scene shows Megan back to her healthy routine, 62 days clean now, and seemingly empowered again. However, we see her watching a fly on her mirror when she comes out the shower, which is ominous because this particular fly was always around a possessed Hannah. Also, as Megan's hair falls across her right eye, we do catch a glimpse of a blue iris.

What's scary about that is Hannah's eyes turned from hazel to blue when she was possessed, and Grainger made it clear it's a mark of the demon. Director Diederik Van Rooijen teases fans with a quick shot, but the blue tinge is unmistakable, leaving it ambiguous whether it's the sunlight hitting Megan's pupil or if the demon has taken possession of her. Throughout the film, the entity had several chances to kill her, but didn't, and seeing as Megan was mentally broken, she would make the perfect vessel. Their final battle did see Hannah screaming into Megan's face, which may have been part of the transference after all.

In theaters now, director Diederik Van Rooijen's The Possession of Hannah Grace stars Shay Mitchell, Grey Damon, Kirby Johnson, Louis Herthum, James A. Watson and Stana Katic.