M. Night Shyamalan's new movie 'Trap' has a twist ending. It's not one of his best, but it leaves the door open for a sequel.

• Warning: Major spoilers ahead for "Trap."
• The new M. Night Shyamalan movie stars Josh Harnett as a serial killer trying to escape a sting at a concert.
• Here's how the movie ends and how it leaves the door open for a potential sequel.

M. Night Shyamalan's latest thriller "Trap" stars Josh Harnett as a serial killer known as "The Butcher." Though the cops don't know what The Butcher looks like, thanks to a tip and the talents of a profiler named Dr. Grant (Hayley Mills), they know he's taking his daughter Riley (Ariel Donoghue) to her favorite pop singer's concert.

After growing suspicious of all the police activity at the concert, The Butcher, whose name is Cooper, finds out what's going on through a talkative concert worker named Jamie (Jonathan Langdon), who reveals to him that the concert is a sting operation to catch The Butcher.

Most of the movie's 100-minute runtime is Cooper figuring out how to get out of the concert undetected. But like all Shyamalan movies, there's a twist at the end.

'Trap' has a twist ending, but it's a little predictable

Cooper does make it out of the concert with Riley thanks to the lax security around pop star Lady Raven (played by Shyamalan's daughter Saleka Shyamalan) after he reveals to the singer that he is The Butcher and will kill his latest victim if she doesn't help him get out of the venue.

However, Lady Raven turns out to have some guts. In hopes of saving the victim, she convinces Cooper and Riley to take her to their house.

There, we meet Cooper's wife, Rachel (Alison Pill), and his son Logan (Lochland Miller). Cooper's entire family is unaware that he's The Butcher, but that changes after Lady Raven steals Cooper's phone, locks herself in his bathroom, and uses it to find the victim's location. As Cooper tries to get into the bathroom, Lady Raven does a livestream to get her fans to figure out where the victim is located and save him.

As the cops race to his home, Cooper escapes with Lady Raven in her limo. Soon after, Lady Raven is able to escape the limo, and once again, Cooper evades the cops.

He heads back home, where Rachel is by herself. He realizes that it has to be her who figured out his double life and raised suspicions to the cops that he could be The Butcher. She confirms his suspicion: It was her who told the cops he would be at the concert.

Cooper is ready to kill Rachel with a meat cleaver, but she tells him that they should have the rest of the cake she made for Riley before the killing begins.

Cooper eats the cake only to realize that Rachel drugged him. Disoriented, he has a vision of his mother at the front door. He had glimpses of her occasionally throughout the movie, but this is the first time she speaks and reveals more about Cooper's troubled life.

As he walks toward the vision of his mother, he's tased by two officers and Dr. Grant, who turns out to really be the person at the door.

Cooper is handcuffed, and while walking to the SWAT van, he stops and is allowed to stand up Riley's bike, which had fallen over on the front lawn. Then he hugs Riley and is driven away.

The camera then pans back to the bike to reveal that the front wheel is missing a spoke. Cut to Cooper inside the van laughing as he uses the spoke to unlock his cuffs as the credits roll.

Finally, in a mid-credits scene, Jamie the concert worker sits on his couch watching the news. A report about The Butcher's capture comes on, accompanied by a picture of Cooper. Jamie is in shock as he realizes he helped Cooper. He vows never to talk to anyone at work ever again.

The ending leaves the door open for 'Trap 2'

Cooper taking off the cuffs is an indication that Warner Bros. is keeping the door open for a sequel. Cooper is a troubled yet extraordinarily clever killer. It would make logical sense for a "Trap 2" to follow Cooper on the run from the police, with Dr. Grant hot on his tail.

However, the prospect of a sequel will likely depend on the movie's box office performance.

"Trap" is in theaters now.