If “The Dark Tower” had just been an action film laced with grand sweeps of magic and textured touches of science fiction based on an original script, there’s enough interesting moments to earn the film a passing grade. The sad fact is it’s not an original story from writer/director Nikolaj Arcel, but based on a wildly popular series of eight books by the master of macabre, Stephen King.

Once the comparisons start, the film ends up a painfully pale version of the books that hop, skip and jump through key points. This flyover approach is such a faint representation of the original product that anyone who has read at least one of the books will feel like the production was made by Arcel aiming to connect with the audience through his eye and his hand and not his mind and his heart.

Unlike the books that start in a barren world that’s home to the last protector of the universe, Roland Deschain (Idris Elba), better known as the last Gunfighter, the tale opens in modern day New York. A youngster, Jake Chambers (Tom Taylor), has been haunted by vivid nightmares for a year. He dreams of a world where a dark figure kidnaps children to use their minds as a weapon to destroy the Dark Tower.

The tower is at the center of the universe and should it fall, the darkness waiting just outside the fringes will come flowing in to destroy everything. His parents are convinced that Jake needs psychological help including a weekend in an asylum.

Jake avoids the program and begins to find clues that reveal these dreams he has been having are in fact visions of another world. He stumbles on a way to make the journey to the land he’s drawn so vividly after his dreams where he meets the Gunslinger. Together, they must stop a powerful wizard (Matthew McConaughey) from releasing the universe-ending evil.

Not only has Arcel stripped the King story of its thick mythology but he’s reduced the production to a standard Old West tale where the lone good guy must face off against the man in black. This includes a series of shootouts in both universes until the final showdown at the just O.K. Corral.

A great actor can help a script, and Elba turns in his usual intense performance breathing life into the Gunslinger that doesn’t come from the writing. He knows just how to play a character with the kind of raw strength that makes most men and women weak but still give the character enough room for an empathy that makes him a friend to the weak. Elba is the biggest saving grace in a wasteland of woes.

For an actor with limited credentials, Tom steps up to make Jake interesting both as an 11-year-old haunted by overwhelming images of evil but also as the best hope for saving the day. Credit Arcel for never pushing the young actor too much, a clever way to eliminate a lot of the places where the young actor could have stumbled.

The weakest casting is McConaughey. He has played his fair share of rogues and villains over the years, but with “The Dark Tower,” McConaughey never reaches the level of being so sinister that his mere presence in the scene causes chills. McConaughey tries to be intimidating and menacing, but his performance never gets any better than it being just all right (all right, all right).

It is sinful that with a mountain of material to work with, Arcel’s script never amounts to much more than a hill of acceptable action element beans. There are hints about the worlds that Jake and the Gunslinger live in having a deep connection from everyone speaking English to an abandoned theme park. But, in what can only be described as an overwhelming desire to get the film done in just over 90 minutes, the final story is like reading a condensed version of the King books done by a group of third graders.

The action is good but that only makes up slightly for all of the writing problems. A list of those miscues could be stacked up to make their own impressive dark tower.

MOVIE REVIEW

“The Dark Tower”

Grade: D+

Starring Idris Elba, Matthew McConaughey and Katheryn Winnick. Directed by Nikolaj Arcel.

Rated PG-13 for violence and language. Check listings for theaters. 1 hour, 33 minutes.

Bottom line: The final story reads like a condensed version written by third graders