Part I Wrath
A mysterious mute Norse warrior only known as One-Eye (Mads Mikkelsen), is held captive up above in misty highlands by a Chieftain (Alexander Morton), where he is forced to fight to the death against other tattooed men. While One-Eye is imprisoned, a young boy tends to him regularly, bringing him food and water. One-Eye is shown to have the ability to foresee events in his dreams; a dream of him bathing in a pond leads him to discover an arrowhead on the bottom of a water bed. Using the arrowhead, he breaks free, slaughters everyone except for The Boy and a warrior who he lets escape, and places the head of the chieftain on a stake.
Part II Silent Warrior
While leaving the land, One-Eye soon realizes that The Boy is pursuing him in curiosity. Together, they reach a small band of Crusaders who have just razed a village. The Crusaders are Christians ready to embark on a crusade to Jerusalem. The leader of the group, The General (Ewan Stewart), asks One-Eye to join him. He reasons that, live or die, One-Eye may cleanse his soul of sin by committing to the Crusades.
Part III Men of God
The Crusaders, The Boy, and One-Eye are on a boat destined for Jerusalem. The crew is broken, thirsty and hungry, and with no wind for several days, a thick fog shrouds them constantly, preventing them from determining their direction or location. Lost, the crew begins to believe that the voyage is cursed, which some attribute to the presence of One-Eye's companion, The Boy. Mutiny nearly arises as a crew member who attempts to murder The Boy is killed by One-Eye. Later, sensing a change, One-Eye takes a drink from the water and discovers that the boat is actually in an estuary and no longer at sea. With the fog dissipating, the crew sees the first sight of land off into the distance.
Part IV The Holy Land
Upon landing, to their surprise, the Holy Land is not a place of vast empty desert one might expect in the Middle East, but rather resembles the taiga, with vast forests full of lakes and mountains. The crew sets out to explore the area, finding no animals to hunt, and no food to eat. Nearly starved, the crew continues until coming across some aboriginal burial sites. One of the crew members, Hauk (Gary McCormack), leaves the group to venture on his own. Upon realizing they have not reached Jerusalem, the crew prepares the ship to depart and head home. While on water, the group is taunted by a single arrow, killing one of their men. Terrified, they soon come to believe that they are in Hell.
Part V Hell
Upon reaching a nearby shore, the men drink a psychotropic brew given to them by their leader. One Eye's dreams begin to intensify, and he wades to a small island to construct a cairn. Meanwhile, the other men break off around the water, and embrace different emotions, including apathy and desperation. Some pray, others wander, others wait. One-Eye and the group are confronted by Hauk who emerges from the forest naked, his skin covered in mud in which runes are drawn. Hauk says he can hear One-Eye's thoughts, and translates that the warrior is saying they are in Hell. The crew becomes divided, with some trying to attack One-Eye in fear, and he kills them.
Part VI The Sacrifice
Arrows from the forest continue to taunt and slaughter ones left behind. Soon after, the band breaks off. The General stays behind, intending to create a new Jerusalem. Hauk only laughs at him. Two of the crusaders, the General's son (Jamie Sives) and the priest of the group (Gary Lewis), follow One-Eye. They reach the top of a tall hill. The Priest sits down and, after talking to One-Eye, the General's son goes back to his father, knowing the man is probably dead and that he will die, too. As One-Eye leaves, The Boy looks on The Priest, expecting him to follow. The Priest only gives the boy a warm smile, knowing he will be safe with One-Eye. The Priest stays behind, mortally wounded by a dagger thrust to his side, dealt to him by the General upon informing him of his intent to depart with One-Eye. He is last seen watching over the landscape, with an aura of light around him, presumably dead and with his sons once more. One-Eye and The Boy successfully reach the coastline and are soon met by a large tribe of Native warriors. One-Eye regards them from a distance before dropping his weapons and walking towards them. They beat him to death. His final moments are a recollection of the cairn he built, slowly submerging himself into the water as he realizes his fate. The tribe leave The Boy alive and venture back into their native land. The Boy (who now has the same aura as The Priest) looks off to the coast, with a dream sequence of One-Eye staring back.