‘The Possession of Hannah Grace’ never fully takes hold

Perfunctory B- movie “The Possession of Hannah Grace” isn’t exactly an earth-shattering entry into the well-worn genre that is the exorcism movie. It doesn’t so much as invite attention to itself as it does to the genre itself, allowing viewers to ponder the ways in which it does or does not hew to convention.

Set in an environment of flickering fluorescent lights and pockmarked poured concrete, “The Possession of Hannah Grace” isn’t really about the possession, nor is it even about Hannah Grace. The film, rather, centers on Megan Reed (Shay Mitchell), a newbie overnight intake assistant at the Boston Metro Hospital morgue whose night is rocked by the arrival of Hannah Grace’s corpse.

A prologue offers the kind of exorcism content we’re familiar with: heavy Catholic i conography, chanting priests, a nubile female body writhing and lashed to a bed. Which is why the most interesting thing about the film is it abandons all that gothic familiarity for a night at the morgue.

Instead of a patriarchal priest compelling demons to get out, a young woman, riddled with PTSD and clinging to 60 days of sobriety, is just trying to get someone to believe her that something’s not right with this body.

One has to wonder just why exorcism films prolif- erate in the way they do. It’s the landmark success of “The Exorcist,” yes, but there’s something else that tickles our collective unconscious: the fetishism and ritual, the bondage, the young female bodies, seemingly so permeable, so changing, so susceptible to invasion by demons that sound like black metal frontmen.

So that’s why when “The Possession of Hannah Grace” zigs where it might historically zag, landing us in the hands of the “smart, resourceful,” but down-on-her-luck Megan, in a refrigerated, automated meat locker, we pay attention. Hannah Grace has a bit more agency than Regan MacNeil, and Kirby Johnson gives a wonderfully physically embodied performance as the corpse who won’t stay still.

At one point, someone wonders to Megan, “Why hasn’t she killed you?” It’s an apt question. She’s a mentally unstable young woman, struggling with addiction and anxiety and trauma — ripe for possession.

But it seems in Megan, Hannah and whatever is inside Hannah (it’s never clear), has met their match, and that’s the place where we should dive further. It’s a bit of a shame the film never draws that out with any clarity.

We simply watch the events unfold with a full understanding of what’s going on. It’s unfortunate that “The Possession of Hannah Grace” just never fully takes hold.

SONY PICTURES/ TNS Kirby Johnson in “The Possession of Hannah Grace.”