Five characters locked in a tiny room. One of them’s a killer. A simple, yet captivating plot sure to get some thrills out of a crowd in any capable hands. The trailer for John Erick Dowdle’s “Devil,” from 2010, put audiences on the edge of their seats…until the name ‘M. Night Shyamalan’ flashed onscreen, at which point they broke into raucous laughter.

Once a renowned director, Shyamalan has been burdened with sour reception for the past decade with flops like 2008’s “The Happening” and 2010’s “The Last Airbender,” though he’s earned all that baggage himself. While Shyamalan isn’t the director of “Devil,” the film is based on a story by him and he holds producer credit. Dowdle, a competent horror director (2007’s “The Poughkeepsie Tapes” is genuinely chilling and shocking), couldn’t save something rotten to the core.

“Devil” follows the cynical Detective Bowden (Chris Messina), who lost his family to a hit-and-run accident. At first investigating a suicide, he soon becomes occupied with an ongoing situation in the same building: Five people are stuck in a broken elevator, and whenever the lights go out, one of them either gets hurt or dies. The roster? A claustrophobic security guard (Bokeem Woodbine), a pissy old lady (Jenny O’Hara), a hysterical young lady (Bojana Novakovic), a mysterious mechanic (Logan Marshall-Green) and a mouth-running salesman (Vince McCormick). Also, an intrusively religious security guard watching over camera named Ramirez (Jacob Vargas) claims one of them is the Devil, and since that’s the name of the movie, he’s right.

While interesting, the concept is far from original. Criminal characters getting whittled down by a killer among them in an isolated location is one of the oldest whodunnit setups, most popularly used in Agatha Christie’s masterpiece “And Then There Were None.” There are also plenty of stories about nameless oddballs locked in a tiny room, trying to get out as tensions rise, like the episode “Five Characters in Search of an Exit” from “The Twilight Zone.” All of these stories are mysteries, through and through. However, thinking of “Devil” as a mystery will only further quell your enjoyment of the film.

The killer is the Devil. You can gather that much from the title. So it’s about finding which one is the Devil, right? No, as the detective understandably doesn’t accept this ludicrous concept until the climax. He and his partner spend most of the film digging up dirt on the five people inside the elevator to find reasonable motives for any of them to kill anyone else. At several points, he is actually successful in his plight, but it’s all for naught, as the Devil himself has no rhyme or reason. Plenty of the characters are connected, but it’s a wasted writing effort. The film should have been called something else. The fact that the crazy security guard is right and the killer is the Devil could have been the big twist.

A still from “Devil” (2010)

So, let’s ignore everything the detective does in trying to find a killer and try to find the Devil ourselves. Are there any hints as to who it is? No. So, we can just go with the flow and see who are the last people standing and pick between them, right? Nope, because the Devil can feign death. When there’s one character left, pick a random dead character; your guess is as good as anyone’s. And it may as well be anyone, considering the Devil’s only conceivable motive is that he’s bored. In fact, it may as well be none of them. This film’s version of the Devil shows that he doesn’t need to stay in a certain body, at points manifesting outside of it. He also has the ability to fly away at any moment. Presumably, he could kill everyone while floating around the elevator in darkness without ever having to reveal himself. All he accomplishes is proving to the world that he exists.

The film tries to justify its concept by making all five of the characters in the elevator criminals, and the Devil wants to take their souls to hell. Thus, we’re not supposed to root for them, of course. But watching them, I’m not angry at them for their evil acts nor their lack of repentance so much as I’m annoyed by the things they say. The dialogue is unreal. It’s made up of unprovoked backstory explanations, stated but unshown traits and cringey quips galore.

The characters are also extremely stupid. One of the few non-annoying characters willingly sticks his foot in an electrified puddle to create a death scene completely disconnected from the Devil’s influence. It’s like the film wants us to sigh and shake our heads at everyone: The good people and the bad people, the wrong people and the right people.

Ramirez, the crazy religious guard, first begins crying Devil when he sees a strange flash in the elevator that looks like a face. From then on, he constantly interrupts the investigation with words his momma told him, prays in Spanish over the speaker for the people in the elevator (which doesn’t make the Devil go away) while ignoring as they’re at each other’s throats over the increased tension, and worst of all, throws a piece of toast with jelly on the floor and claims the Devil made it land jelly-side down. Yet, he’s the right one.

What’s the message? It can only be one of gratification for very religious viewers, but what very religious person would watch a horror film called “Devil?” It’s much too violent and profane to appeal to that base.

Then again, it doesn’t go far enough to appeal to horror fans, either. The film retains a PG-13 rating, cutting away or snapping to black every time someone is about to get killed. We then see a quick, unimpressive flash of the aftermath. It’s hard to believe this film cost $10 million to make, seeing as most of it takes place in one tiny room, the cast is a bunch of people you’ve never heard of before and almost every bit of action is skipped over.

SHOULD YOU WATCH IT? “Devil” is a terrible mystery film, a boring horror film and a confused religious film. It appeals to no crowd except challenge watchers: those who seek out bad films just to try and get through them. Even so, the film’s short 80-minute runtime makes it an easy task.

WATCH IF YOU LIKE: Any of M. Night Shyamalan’s other films from the past ten years. This is one of the least of his sins.