By Lynn Venhaus
Ancient warriors look contemporary, but their secret is that they are immortal – well, sort of (you’ll see). This covert group of mercenaries has fought to save the world for centuries.

Action-packed, “The Old Guard” has a premise that propels you through caves, deserts, contemporary offices and centuries-old flashbacks. It’s quite the road less traveled.

The gang of four who make up this human shield of protection are: Charlize Theron as the leader Andy, who might be about 6,000 years old, give or take a few; Matthias Schoenaerts as her right-hand man Booker ; and Marwan Kenzari and Luca Marinelli as Joe and Nicky, a gay couple with fierce loyalty.

When they are recruited for an emergency mission, it’s a set-up and their extraordinary abilities are suddenly exposed. Big Pharma wants to monetize their power but can they avoid detection? The tight-knit four are joined by a new soldier (KiKi Layne). This story is based on the graphic novel by Greg Rucka, who wrote the screenplay, and illustrated by Leandro Fernandez.

Director Gina Prince-Bythewood displays her versatility, helming a massive blockbuster after more contemplative pieces “Love and Basketball” and “The Secret Life of Bees.”

Charlize has proven she is a formidable action star, in “Mad Max: Fury Road” and the highly underrated “Atomic Blonde.” And again, she is mesmerizing – long and lean, and a world of hurt and trouble etched on her face.

The quartet’s bond is special, and that sets this supernatural action movie apart – there is depth to the characters. After all, they have lived extraordinary lives.

They are joined by a reluctant Nile, a Marine stationed in Afghanistan. Kiki Layne, a rising star who was so good in “If Beale Street Could Talk,” holds her own here.

While the concept is intriguing, the dialogue is a letdown. It’s basic, even trite. The graphic novel author, Greg Rucka, adapted the screenplay, so it’s very by-the-book.

The film is also brutally violent, and the implement of choice is often assorted swords, so there is a great deal of slicing and dicing.

Blood-soaked and too long (2 hours, 5 minutes), “The Old Guard” isn’t perfect, but its selling points are good ones. And it sets itself up for a sequel. You know it’s coming.

Charlize Theron as fearless leader Andy in “The Old Guard”

“The Old Guard” is an action movie with supernatural elements — it is not a superhero movie. Directed by Gina Prince-Bythewood, it stars Charlize Theron, Kiki Layne, Marwan Kenzari, Luca Marinelli, Harry Melling, Matthias Schoenaerts and Chiwetel Ejiofor. It is rated R for sequences of graphic violence and language, and has a run-time of 2 hr. 5 min. Available on Netflix as of July 10. Lynn’s Grade: B. A version of this review is in the Times newspapers online.