In “The Eagle” Kevin MacDonald (“The Last King of Scotland”), directs a narrative about Marcus Aquila Flavius, a morose, hard-nosed Roman soldier (pretty boy Channing Tatum) as he searches in vain for the golden eagle of Rome — and a viable plot.

Marcus is introduced as the son of the Roman military commander who led 5,000 men and a golden eagle totem into the backwoods of northern England, never to be seen again. The shame and notoriety of his father’s mistake — losing the prized eagle, the sign of Rome — constantly haunts him. Guilt-ridden, Marcus is driven to take a position as a commander in the shit-smelling bowels of southern England, where he’s injured trying to save his men.

The movie only begins after 30 minutes of meandering anguish, and this opening sets the tone. Marcus is featured as a capable warrior, a depressed patient and the eventual owner of an English slave named Esca (Jamie Bell), who Marcus saved from death in a gladiator ring. Tatum and Bell take off across gloomy Scotland, turning what could have been a fairly interesting bonding experience between two budding friends into a shameless display of testosterone-fueled passive-aggressive angst. The rest of the plot isn’t bad so much as overly familiar — there’s bonding, backstabbing and dramatic fight scenes (see also: “Mean Girls”) and eventual back-patting resolution.

For a movie that relies so much on the grit of its fight sequences, “The Eagle” displays a nauseating misunderstanding of combat style and canon — battles induce headaches, as if shot in the midst of an earthquake, making it difficult to focus on images of flashing swords and metal. The editing also mutes the film’s bloodshed, skirting around throat-slittings and stabbings, ultimately steering clear of the bloodlust that successful blockbusters “300” and “Gladiator” fed on.

The duration of “The Eagle” finds Tatum nailing his singular facial expression: the furrowed scowl, pioneered by emo kids worldwide. Bell carries the film, squinting, shivering and gasping from heavy blows, coolly assessing a grey countryside and barking insults at his superior — his Esca is remarkably resilient and scrappy.

But neither actor is helped by the clunky dialogue that limps along for the length of the film in a more affected gait than Marcus after his injury. Lines lacking spark are delivered with monotone, inspiring apathy toward the characters and their words.

While inoffensive, the movie’s uninspiring, boilerplate approach to period drama has us revisiting Russel Crowe’s infamous “Gladiator” question: “Are you not entertained?” The jury’s still out. (C-)