With a smarter, tighter screenplay, "A Perfect Getaway" might have been a gritty, no-frills, tension-fraught thriller. Sadly, writer-director David Twohy (2004's "The Chronicles of Riddick") botches the results in more ways than one, culminating in a turn of the narrative screws that maddeningly condescends to those viewers with a functioning brain. It is fine and well, even ambitious, to endeavor upon a motion picture with a twist ending that evades the audience's expectations and surprises them. The key to success, however, is the need for aforementioned revelation to make logical sense within the story, bearing in mind all that has come before it. The recent chilling "Orphan," for example, achieved this feat splendidly. The increasingly moronic, ultimately nonsensical "A Perfect Getaway" does not. Picking out the plot holes is as plentiful as picking flowers from a poppy field in springtime.

Newlyweds Cliff (Steve Zahn) and Cydney Anderson (Milla Jovovich) are on their honeymoon in Hawaii, drinking in the exotic sights and breathtaking vistas as their bright future stands before them. While hiking the scenic, 11-mile Kalalau Trail, they learn from a trio of young backpackers that another pair of just-marrieds have been found brutally murdered in nearby Oahu, the latest victims of a serial killer team on the prowl. Cliff and Cydney agree to hike the rest of the trail with Iraq War vet Nick (Timothy Olyphant) and southern girlfriend Gina (Kiele Sanchez), but paranoia takes over when they begin to suspect their new acquaintances are two bananas short of a fruit basket. Also suspects: a bohemian couple Cliff and Cydney previously had a strained run-in with, Kale (Chris Hemsworth) and Cleo (Marley Shelton), lurking on the trail, too. To make matters even worse, someone else altogether seems to be following them.

For the first two-thirds of its running time, "A Perfect Getaway" is an absorbing slow-burn genre piece where happy-go-lucky protagonists find themselves isolated and suddenly placed in a potentially life-threatening situation. Although Cliff and Cydney do not know who the true culprits are—or, for that matter, if they are even in contact with the killers—there is the sneaking suspicion that danger is imminent. Writer-director David Twohy takes his time setting up Cliff and Cydney as likable and in love, and then slowly draws them into a web of threat that has them questioning their own safety and the validity behind Nick and Gina. Are these two merely a couple also on vacation, eccentric but harmless, or is there an ulterior motive permeating beneath the surface? Twohy effectively toys with this question as Cliff and Cydney try to keep cool until they can reach the beach at the end of the trail.

Indeed, the film has some tricks up its sleeve, but said tricks work about as well as a magician striving to pull a rabbit out of his hat and only finding an empty hat. Based on what occurs during the first hour, the last thirty minutes are a cheat. Director David Twohy does not play fair with the viewer, and to an enraging degree. He can't even depict the reveal with any degree of class, instead jumping into an ungainly, nearly 15-minute-long series of flashbacks that are supposed to explain all the clues and reveal the truth of certain situations leading up to the twist. The longer this montage of scenes goes on, the more ridiculous it becomes. Interesting, too, that in this overextended segment Twohy dodges explaining the very parts that do not make sense in light of the third-act plot divulgement. This is lazy screenwriter beyond belief, and it is amazing these flaws in Twohy's grand design weren't fixed before production got underway.

The female cast members fare better than their male counterparts. The usually reliable Steve Zahn (2009's "Management") overplays the on-edge nervousness of Cliff, a professional screenwriter whose first movie is about to go into pre-production, while Timothy Olyphant (2007's "Hitman") acts too off-kilter from the start to believe that Cliff and Cydney would agree to go off with him—especially after finding out about the murders. As Cydney, it is nice to see Milla Jovovich (2007's "Resident Evil: Extinction") in a down-to-earth role rather than the one-note action/sci-fi heroine persona she has become best known for. She is terrific, as in a scene where she talks to Gina about the plans she and Cliff have together, and the haunting memories of her past that she is looking to run from. As Gina, Kiele Sanchez (2007's "Mr. Magorium's Wonder Emporium") is a beguiling presence and a treat to watch, picking up a charming southern accent that may or may not hide a vicious soul.

The further "A Perfect Getaway" presses forward, the deeper the hole gets that it digs for itself. In addition to a climax that doesn't hold water, the actions of the characters become all the more imbecilic. From the artificial, too-talky self-referential dialogue of the lead characters that rips off 1996's "Scream" and its two sequels, to a truly insulting and naive portrayal of law enforcement, the movie tosses anything and everything at the screen without a moment's thought to coherence or reason. Appealing photography of the Puerto Rican coast, standing in for Hawaii, doesn't cut it when a film's script is as troubled and patronizing as this one is. For the promise it held at the onset and the foolishly inane places it opts to travel to, "A Perfect Getaway" is a particularly arrogant letdown, a thriller with a rancid bite.