I always make sure to check in on writer-director M. Night Shyamalan’s films just to see if they ever improve. Shyamalan is notorious for what a charitable person might call his “unevenness” as a filmmaker. In a long career, he’s gone from the heights of extremely effective and wildly successful films, with The Sixth Sense (1999) as the primary example, to the depths of abysmally silly films that deserve to fail, as in the case of the notoriously extravagant bomb Lady in the Water (2006). He’s rebuilt his career with varied gambits like self-effacing, purely commercial hits (The Last Airbender) and, more recently, low-budget, self-financed, auteurish endeavors that guaranteed him total creative control (The Visit, Split, Glass, Old, Knock at the Cabin).

You’ve at least got to give him credit for adaptability.

Trap is his latest, and it’s getting more mainstream hype than most of his recent films. This one is a psychological thriller about a kindly firefighter and proud father named Cooper Adams (Josh Hartnett) who’s taking his thirteen-year-old daughter Riley (Ariel Donoghue) to one of those pop-star concerts where the kids can scream out their enthusiasm and sing along obsessively with the lyrics, while the parents pretend to be entertained but mostly zone out.

The star is called Lady Raven, and she’s played by Shyamalan’s daughter Saleka, who wrote and performed fourteen songs for the film. It seems Saleka actually is an aspiring pop singer who’s opened for acts you’ve heard of. She may be a talented singer — I can’t judge these current pop stars; they all sound terrible to me — but she’s definitely no actor. So if after a while you’re wondering why the film is spending so much time at the concert, dwelling on so much Lady Raven footage and then later showcasing her in whole dramatic scenes that she’s by no means up to playing, it doesn’t take a cynic to figure out that this is a case of a nepo baby on steroids.

Anyway, if you’ve seen the film’s previews, you know that the concert is also the site of a massive sting operation. It seems the FBI has been tipped off that a serial killer known as “the Butcher” is attending the concert, and there are hordes of heavily armed police blocking every exit once the concert begins. There’s an expert profiler (Hayley Mills) helping to coordinate the vast operation.

Spoiler alert! The film’s rather alarming plot wrinkle is that nice dad Cooper appears to be the Butcher. And he’s going to spend the entire concert trying to figure out how to escape without alerting his daughter to his nefarious alternate identity. The film takes on a creepy gloating quality when somebody says to Cooper regarding an apparently lucky break that gives Riley a chance to go onstage with her idol Lady Raven, “Your daughter will never forget this day as long as she lives!”

It’s an unpleasant premise.

So much so that you might wonder if this film will feature one of Shyamalan’s familiar plot twists, somehow exonerating Cooper and showing how he’s not actually the Butcher after all, though how Shyamalan would manage this is impossible to project. Anyway, there’s no use pursuing that idea, because Cooper is the Butcher, as the film makes clear early on. Cooper goes to the men’s room and while in the privacy of a stall, takes the opportunity to check on his cell phone’s live feed of his latest captive, a panicky young man named Spencer, pacing the floor in the basement of a vacant house nearby, where the Butcher has him trapped.

Not a spoiler! That really is the plot of the film from the start!

Fortunately for the viewer, Josh Hartnett is still handsome and charismatic long after his young heartthrob years. And he’s a pretty good actor too, so you have something worth watching as he maneuvers and manipulates and does quick-change impersonations of concert venue workers in order to steal an apron and a clip-on access keycard and gain admittance to the storage room, the basement, the rooftop, the backstage area, anyplace that might offer an unguarded escape route. He’s so slick at this, it’s clear that even as he’s sweating his own entrapment, he’s also getting a thrill out of putting his own superior role-playing abilities to the test.

Hartnett is carrying the film well until Shyamalan torpedoes him through absurd plot developments that keep getting sillier till nobody could pull them off — not the greatest actor in the world, not even Daniel Day-Lewis at the top of his form. When the sweet but spacey pop icon Lady Raven — a kind of Taylor-Swift-meets-Lady-Gaga-meets-Bollywood-star figure of tremendous fame and pampered wealth — starts leading the dangerous quest to match wits against the Butcher in order to save Riley and her family, you’re so far over the rainbow you’ve changed genres from psychological thriller to hallucinatory fantasy.

But long before that insane development, the wheels are coming off the cart through typical Shyamalan excess. His stunt casting of Hayley Mills (of The Parent Trap and Pollyanna fame) in the profiler role is distracting and wrongheaded. And I say that as Hayley Mills’s biggest fan. Even if you don’t know who Mills is, you’re liable to wonder why a thin, frail, lovely, elegant, but very elderly British lady with the poshest English accent since Queen Elizabeth II is practically running an FBI manhunt and issuing tough commands through a walkie-talkie.

And then there’s Shyamalan’s cameo, that stupid thing he always does as if he were a latter-day Alfred Hitchcock and audiences were waiting eagerly to see where he’d turn up in his new movie. In Trap, he plays a Lady Raven factotum who manages a segment of her concerts involving the “Dreamer Girl,” a teenager chosen from the audience to come up on stage and join Lady Raven in performing a song. It’s an absolute howler when Cooper/Butcher realizes that his only way out may be the backstage exit, and he zeroes in on Shyamalan’s character standing anonymously in the aisle, dressed like any other venue hireling. It’s as if he’d had a sudden, unerring ESP vision that this is the guy who can get him backstage, if Riley is chosen as the “Dreamer Girl.”

It’s really too bad that Shyamalan has nobody to tell him when he’s gone off the rails. He could’ve been a very solid commercial director with a good reputation. Instead, he’s this strange case study of a delusional egoist brooking no interference from anybody who once wrecked his own ultrasuccessful career by creating unhinged cinematic train wrecks out of sheer hubris, then rose from the ashes because he’d made so much money on early film successes, he could never be truly down and out in Hollywood. And he goes blithely on as a source of morbid critical fascination, wrecking and rising, wrecking and rising.

Trap is more on the wrecking end of Shyamalan’s fever-chart career trajectory. It’s being critically trashed. Though who knows, it may make money. And Shyamalan must be so used to these dizzying rises and falls by now, they become just another day at the office.