Before the arrival of the second millennium in 922 A.D., the vibrant city of Baghdad stood out as the pinnacle of civilization. It is within this illustrious backdrop that Ahmed Ibn Fahdlan, portrayed by Antonio Banderas, a gifted poet enjoying a privileged existence, makes a grave mistake when he attempts to woo a married woman. This indiscretion draws the ire of her jealous husband, who happens to be a friend of the Caliph, resulting in Ahmed being dispatched as an ambassador to the far-flung Nordic realm of Tossuk Vlad—a noble yet dubious exile from his beloved city.

Embarking on a journey with his mentor Melchisidek, played by Omar Sharif, Ahmed’s caravan is set upon by a marauding band of Tartars. However, their pursuit is soon halted when they spot a Viking ship approaching the shore. As they reach the Viking camp, they witness the revelry of a lively celebration. Through the efforts of Melchisidek, Ahmed learns that the raucous festivities are, in fact, a solemn funeral for the late king. It’s here that he meets Buliwyf, the heir apparent, brought to life by Vladimir Khulich. The might of Buliwyf is immediately felt when he swiftly dispatches an attacker, solidifying his claim to leadership amidst the grim events unfolding.

Despite the initial allure of Viking festivities, Ahmed becomes increasingly appalled by their customs—their lack of hygiene and their gruesome human sacrifices do little to endear him to this culture. The following day, a messenger arrives, seeking Buliwyf’s assistance against a mysterious and deadly foe known only as an ancient evil by the Vikings. This prompts a divine claim from an old soothsayer who decrees that a band of thirteen warriors, including Buliwyf, must journey forth to vanquish this threat.

As the selection for warriors progresses, the soothsayer insists that the thirteenth must be a man from the South. With pressure mounting and eyes upon him, Ahmed is reluctantly thrust into the fray and granted a new name—Eban, which the Vikings use to denote him throughout the journey. From this point, Ahmed redirects his efforts to understand his companions, immersing himself in their language and culture. Observing from the sidelines, he studies their interactions until he is able to articulate his thoughts in their tongue when a slight against his mother ignites his passion.

The days unfold with trepidation as Eban impresses Buliwyf with his ability to read and write, revealing his capacity to bridge worlds. Eban’s Arabian horse, far smaller than those of his Viking companions, quickly becomes a point of jest. Nonetheless, through a series of humorous yet defiant displays, he earns their respect when he showcases the horse’s remarkable jumping ability, a feat that is met with admiration from Buliwyf and Herger. A moment arises during their journey where Eban witnesses the Viking’s strength in battling the elements and each other.

Their adventures eventually lead them to Venden, a kingdom devoid of defenses, ruled by King Hrothgar and his disdainful son Wigliff. Within the chaotic backdrop, they learn of the terrifying Wendol—monstrous creatures that terrorize the populace. Eban, witnessing the devastation brought by the Wendol, valiantly participates in the imprisonment of one such creature, revealing them to be mere men disguised in fearsome garb.

As the battle intensifies, Eban finds himself wielding his sword with newfound ferocity, leaving behind the timid poet he once was, transforming into a fierce warrior whose blood runs cold with rage against his enemies. The gruesome conflict takes its toll, and the losses mount, yet a flicker of hope remains in Buliwyf’s bravery and wisdom as he continues to lead them forward even in the face of death.

Alongside his comrades, Eban witnesses the fragility of life, and as they recover from a near-fatal encounter that marks them deeply, a profound sense of brotherhood begins to cultivate amongst the warriors. It becomes evident that the bonds forged in battle run deeper than any differences between them. Ahmed subsequently realizes the purpose behind his journey, facilitating his transformation not only into a warrior but also into a storyteller.

As the warriors prepare for the decisive battle, Buliwyf, weakened yet undeterred, rallies his men with a stirring Viking prayer that would echo through history. In the clashing tides of war, Buliwyf’s valor spurs the men to push back against the Wendols and their merciless onslaught, solidifying his legacy as a true leader and protector.

In the aftermath of battle, with victory secured but loss lingering in the air, Ahmed returns to Baghdad forever changed. Grateful for the life lessons imparted by the Norsemen, he dedicates himself to chronicling the extraordinary saga of his journey with them, ensuring that the tale of the brave warriors—who taught him the meaning of honor, courage, and friendship—will not fade into the mists of time. He writes not just of glory, but of transformation, emerging from his era as the thirteenth warrior destined to carry their legacy forth into history.