Josh Hartnett goes big as a serial killer in 'Trap'

“Trap” — 2.5 stars

In our spoiler phobic culture, movie trailers don't often offer a lot of information. It's even dangerous territory for a critic to discuss too many specifics, sometimes years after a film or television show has come out.

So it seemed like a particularly bold and even confusing move for " Trap,” the latest film from M. Night Shyamalan, to reveal so much so soon. Namely, that the nice guy dad played by nice guy actor Josh Hartnett taking his teenage daughter to a Taylor Swift-like arena concert is a brutal serial killer. Not only that, the entire event has been manufactured to trap him.

Doesn't seem like something that a filmmaker known, or at least stereotyped, for his twists would do. Obviously there must be something else going on, right?

Perhaps that something else is that “Trap” really doesn't take itself that seriously. It is a solidly entertaining film that's mostly silly and sometimes unnerving. You're not exactly rooting for Hartnett's Cooper, whose energy is so manically enthusiastic in his casual interactions with strangers and acquaintances that it takes some getting used to. But you are drawn in enough to be ever curious about his next move.

Hartnett, fresh off a stately turn in “Oppenheimer,” is not going for naturalistic with this performance. He's a psychopath trying, not very well, to keep his devilish side at bay. When he smiles and attempts pleasantries, it looks almost painful. His energy is intense and a little uncomfortable. If Hartnett was born just a little earlier, you could image him as part of the original “Twin Peaks” cast — even his name seems to be a nod.

And here, Cooper's supervillain power is being able to seamlessly pass as the normal suburban dad just trying to show his daughter (Ariel Donoghue) a fun time. That is soon dashed when a friendly arena employee decides to clue him in on the big plot to catch The Butcher. One thing “Trap” does especially well is exploit the ways in which a guy like Cooper — attractive, confident, white — can pass almost anywhere.

Much of the film transpires at an arena concert full of teen and tween girls obsessed with a pop star called Lady Raven, played by Shyamalan's daughter, Saleka Shyamalan, who wrote 14 songs for the film. It's quite the hard launch for an up-and-coming performer, but it's an admirably bold one too. “Everyone needs a break when they're starting out,” she says to the crowd at one point. “Trap” commits to the bit, too, making you feel like you are on the ground floor experiencing a concert in real time. But if you went in hoping for “Die Hard” in an arena, be prepared for something else.

“Trap” does have some things up its sleeve, including a solid and unexpected acting performance from Saleka Shyamalan. It also feels a bit underbaked, a ridiculous ride that's not going to get under your skin or provide for a lot of discussion fodder afterward.

While it's great to see Hayley Mills, regal as ever, as the mastermind of the police operation, she's not given much to do besides narrate. But maybe there's not meant to be some grand there there, like some startling revelation about parenthood or marriage or pop stardom or even sociopaths. We keep wanting Shyamalan to somehow give us “The Sixth Sense” or “Signs” again. “Trap” is not either of those. This is a popcorn movie, with a surprising turn from an underrated star. And ultimately, it's a pretty fun time at the theater.

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A Warner Bros. release now in theaters, rated PG-13 for “brief strong language, some violent content.” Running time: 105 minutes.