What makes matters worse: The annoying ending not only makes little sense, but also ruins a great James Brown song.

I understand that horror movies ask us to accept their premise without much discussion, but Kravitz and ET Feigenbaum’s script constantly changes the product. Are we being treated to a vicious parody of reality shows where women party and try to outdo each other for the benefit of hideous male contestants? Is this a satirical takedown of toxic masculinity and bro culture? Or is it a dig at America’s unwise worship of the rich?

What can we learn from this film? The story follows several women, including our heroine Frida (Naomi Ackie), who impulsively hop on a plane with a group of suspicious (and rich) tech bros and fly to a private island from which there is no escape. None of them think it’s a bad idea. They even hand over their cell phones when they land in a place where there is no landline.

The owner of this private island is Slater King (Channing Tatum), a tech billionaire who first apologizes on social media for an indiscretion. We assume it’s some form of indecency towards women, because that’s the only thing that makes these powerful men send such insincere messages: “I’m sorry for my behavior and I’m going to therapy now.”

We also assume Slater is a psychopath, as he has the typical beard of a movie madman. You know the kind – Burl Ives in the front and Kenny Rogers on the sides. Although he handles the facial hair well, Tatum is woefully miscast. He just can’t play a good madman. In this film, Magic Mike was cast when Marky Mark was needed.

Slater’s pals are played by a whole host of actors – Christian Slater, Haley Joel Osment and Simon Rex – who are better at conveying dirt than Tatum. Twin Peaks’ Kyle MacLachlan is Slater’s bespectacled therapist, who seems innocent (but we know better).

Just for a change, Slater’s assistant is played by Geena Davis. If you don’t think she’s capable of extreme violence, you haven’t seen The Long Kiss Goodnight.

Although “Blink Twice” aims to make a feminist statement, it is ultimately just a slasher film with a series of one-dimensional final girls, played by Alia Shawkat, Trew Mullen, Liz Caribel and Adria Arjona from “Hit Man”.

They spend the first half of the film drinking, getting high on various substances, and lounging by the pool. Kravitz repeats these scenes over and over, which are neither visually interesting nor reveal much about the characters. The film looks like a boring reality TV show, which is something the original title alluded to better than the current one.

I would be more forgiving if Frida wasn’t so poorly written. She spends most of her screen time trying to impress Slater with lovestruck looks like she’s a lovesick teenager. She also makes incredibly stupid mistakes – even the first victim in a Friday the 13th movie would know better.

Frida begs Jess (Shawkat), the concerned roommate who has accompanied her on this journey, not to ruin her “only chance to be seen.” The film doesn’t bother to explain Frida’s hopes and dreams up front. Seen where? And by whom? Is she just out to lure a rich man, even if he tries to kill her – or worse?

When Frida gets a glimpse of Slater’s intentions, scenes of bloody violence, rape, and murder take over. This is common in exploitation films, but I question the use of childhood sexual abuse as a justification for villainy. The plot relies on the idea that we want to forget traumatic experiences, but then sets up the ridiculous idea that we should be forced to relive and repeat sexual trauma over and over again as part of the healing process.

Only Arjona shines as Sarah, one of the island visitors who has been competing on a reality show called “Hot Survivor Babes” for 20 years. She brings the proceedings to life, especially when she springs into action during the film’s vengeful climax.

Throughout the film, Slater takes Polaroids of his victims and asks, “Are you guys having fun?” As I sat in the theater, decency prevented me from shouting, “No way!”

★½

FLASH TWICE

Directed by Zöe Kravitz. Written by Kravitz and ET Feigenbaum. Cast: Naomi Ackie, Channing Tatum, Adria Arjona, Christian Slater, Haley Joel Osment, Simon Rex, Kyle MacLachlan, Alia Shawkat, Trew Mullen, Liz Caribel. At AMC Boston Common, Landmark Kendall Square, Alamo Drafthouse Seaport, AMC Causeway, Suburbs. 102 minutes. R (graphic depiction of sexual harassment, profanity, blood)

Odie Henderson is the Boston Globe’s film critic.